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Everything You Want to Know About Laterite!


  1. Laterite - the whole story
    by Earle Hamilton <> (Fri, 18 Aug 1995)
  2. Laterite balls/shards: low surface area
    by Charley Bay <> (Mon, 21 Aug 95)
  3. A discussion of substrate additives
    by (Tue, 22 Aug 95)
  4. "other" laterite substrates
    by (Fri, 1 Sep 95)
  5. Hot Gravel & Laterite source
    by Earle Hamilton <> (Tue, 15 Aug 1995)
  6. Laterite clouding and 230g update
    by Earle Hamilton <> (Tue, 5 Sep 1995)
  7. Laterite and ugf
    by Earle Hamilton <> (Tue, 5 Sep 1995)
  8. Clay
    by Tyson Lee <> (Wed, 3 Jan 1996)
  9. Price of laterite at Laguna Clay
    by gtong-at-SIRIUS.COM (G.Tong) (Mon, 25 Sep 1995)
  10. Soil Substrate
    by mccarten/ (niall mccarten) (Sat, 1 Mar 1997)
  11. Re- Laterite "Mined in the
    by "Mark Shelton" <mark_shelton/> (9 Mar 1997)
  12. processing laterite
    by George Booth <booth/> (Thu, 15 Jan 1998)
  13. Fe2+ / Fe3+ [long but hopefully interesting]
    by Neil Frank <nfrank/> (Thu, 23 Apr 1998)
  14. Laterite, Arcillite?!
    by "A. Inniss" <andrewi/> (Mon, 30 Mar 1998)
  15. Laterite, Arcillite?!
    by Beverly Erlebacher <bae/> (Tue, 31 Mar 1998)
  16. Questions
    by Steve Garinger <sgaringer/> (Thu, 14 May 1998)
  17. Substrate, Laterite
    by Roxanne Bittman <rbittman/> (Thu, 9 Apr 1998)
  18. Iron and substrates
    by krandall/ (Sat, 28 Nov 1998)
  19. Laterite and clay
    by "Roger S. Miller" <rgrmill/> (Sun, 24 Jan 1999)
  20. Laterite
    by "Roger S. Miller" <rgrmill/> (Fri, 5 Feb 1999)
  21. "Real" laterite
    by "James Purchase" <jpurch/> (Fri, 5 Feb 1999)
  22. sigh...laterite
    by Alysoun and Andrew <alysoun/> (Wed, 27 Jan 1999)
  23. Laterite
    by krandall/ (Mon, 08 Feb 1999)
  24. RE: Ducks, Laterite and Clay... Amen!
    by "James Purchase" <jpurch/> (Mon, 8 Feb 1999)
  25. RE: Laterite
    by "James Purchase" <jpurch/> (Fri, 5 Feb 1999)
  26. ?Laterite injectible?
    by "ALEX PASTOR" <alexp/> (Sat, 6 Feb 1999)
  27. Just for the record
    by IDMiamiBob/ (Tue, 9 Feb 1999)
  28. laterite.....Substrate Gold
    by Karl Schoeler <krsfert/> (Sat, 06 Feb 1999)
  29. Re:Dosing levels for Substrate Gold
    by Karl Schoeler <krsfert/> (Sat, 13 Feb 1999)
  30. Feldspar -> clay (kaolin, bentonite, etc.) -> laterite
    by Wright Huntley <huntley1/> (Thu, 25 Feb 1999)
  31. Baking potter's clay -- time
    by Wright Huntley <huntley1/> (Fri, 26 Feb 1999)
  32. What's the truth about laterite
    by "Roger S. Miller" <rgrmill/> (Mon, 3 May 1999)
  33. (No Title)
    by ()
  34. (No Title)
    by ()
  35. Laterite
    by "Roger S. Miller" <rgrmill/> (Thu, 8 Apr 1999)
  36. Laterite
    by Steve Pushak <teban/> (Mon, 12 Apr 1999)
  37. Oregonn laterite
    by "Roger S. Miller" <rgrmill/> (Wed, 15 Mar 2000)
  38. (No Title)
    by ()

Laterite - the whole story

by Earle Hamilton <>
Date: Fri, 18 Aug 1995

I hope you all appreciate the fact that I'm very lazy and don't like 
being bothered by having to make this entry but hopefully it will be my 
last post on the subject.

What is laterite?  A high iron clay formed in tropical areas.  Most of 
commerical laterite is mined from the US in areas that were tropical 200 
million years ago.  Where I live in northern Mich we have Petoskey stones 
formed 260 million years ago (they are focillized coral) which further 
proves this area was once tropical.  At any rate, you don't have to be in 
the tropics to get laterite.  Georga red clay may be a type of laterite 
for all I know but since it is not a normal source the Fe content is 
probably low.

Why is it so expensive?  Packaging, shipping and commercial greed!  Think 
about it - if you had the market cornered (for aquaria) how much money 
could you make.  A.  Not that much really since there aren't that many 
people out there that want to bother with substrate heating etc.  The 
authors of THe Optimum Aquarium did a fantastic job of isolating all the 
things that guarentee success and it is only natural they expect to be 
paid for their research.  In a sence I am being very unethical to suggest 
lower cost alternatives but then people are doing DIY co2 yeast units, 
alternate substrate heating - etc.  It is important to know why you are 
doing something so I suggest before anybody jumps into this they read TOA 

Chemical breakdown. - got it for "red art clay" but don't have a clue 
what Dupla's is.  It would be nice to get a post from somebody who 
analyzes Dupla.   I suspect it will be close to red art clay.  Even if 
the Dupla stuff is higher in Fe that means we might use a little more of 
the almost free stuff. (A package of Dupla works out to about $50 a 
pound). Chemical analysis:      SiO2    64.27%
                                AlO3    16.41%
                                Fe2O3    7.04
                                TiO2     1.06
                                CaO       .23
                                K2O      4.07
                                MgOO     1.55
                                T2O5      .17
and there are other things the vendor will give if you ask but that gets 
most of the stuff.

Source?  A.R.T.
         1555 Louis Ave
         Elk Grove Village, Il 60007-2313  Phone 1-800-323-0212
 or 708-593-606.   Ask for Chuck ( talked to him this morning and warned 
him he may get a call or two).

Cost $$$?       50#     $11.00
                25#   available but I forgot to ask price
                 5#       3.00
Catch - minimum order is $30 or there is a $5 handling charge.  Shipping 
by UPS is, or course, extra.

Remarket through this plant list?  Good idea and I wanted to do it, but 
like I have said before, I am not a type A person like when I worked for 
GM so I don't want to be bothered.  Dupla sells the powder and 
"pellets".  At one time the fellow who is the potter and I talked about 
marketing this stuff and would have mixed up a batch of clay and run it 
through the extruder he has.  We would then cut off hunks similar to 
Dupla that would be about the size of a marble.  FIRING THESE CHUNKS 
WOULD DEFEAT THE PURPOSE OF THE LATERITE.  It has been suggested we could 
get laterite in our tanks by breaking up clay pots.  The stuff used for 
clay pots has very little iron and I suspect firing bonds the stuff 
together in a way that would be of little use to plants.
I have seen no evidence that the clay chunks are of any real value.  They 
do hold up well and are easy to form from the powdered laterite from 
Duply or A.R.T.  If you work with this stuff you will find it takes very 
little water and that the result is very sticky goo but it is easy to 
make up the marbles.  Would be a great project for a fish club.

Other Sources - Rouin Ceramics
                15333 Racho Rd
                Taylor, Mi  48180  phone 313-474-0010. (I did not talk to 
them and figure my phone bill is big enough).

  other other sources ---probably a bunch.  Check your local potter and 
work with him/her.  You will find the analysis of all these clays is not 
secret and you can compare.  Obviously you want the highest Fe content 
you can get.  To carry this to an extreme it would be interesting if 
somebody put a sheet of soft iron sheet metal in the bottom of their 
tank.  That way you would be at near 100%.  The process involved in 
plants taking up iron is very complex and beyond my limited education but 
I am smart enough to know the answer is fairly complex.  I do know that 
with either the Dupla or "cheap" laterite that the Fe test does not show 
a high iron content from just using laterite.  It is still necessary to 
use liquid fertilizers.  

What's next?  For me, nothing - I'm going back to play with the fish.
The profit is not going to be fantastic so this will be a labor of love 
but I hope through the postings that agreement can be reached on how to 
do it for the most good to the most people.

How much laterite do you need for a tank?  Tables have been published 
here from TOA.  For gallons divide liters by 4 and you will be close enough.
Tank size in liters  in gallons         grams laterite   lbs laterite
110                     25                      250       1/2
200                     50                      500       l  (454g/lb)
350                     87                     1000       2
520                    130                     1500       3

On page55 of TOA I read "The iron contaiing additive is mixed with the 
actual substrate used in a ratio of approximately 1 to 3 before it is 
placed in the aquarium, and the mix thus prepared makes up the bottom 
layer of the substrate.  This is then covered up with the balance of the 
substrate ...".  I took this litereally before I studied the table given 
above and ended up with many times the table value.  I would guess 
laterite has a specific gravity of close to 2 so either by volume or 
weight the 1/3 of 1/3 would give close to 10% by weight or volume of the 
total substrate.  A good rule of thumb is 2# of gravel for every gal of 
tank size which would make the 130 gallon tank above have about 250 
pounds of gravel and mixed in the bottom 1/3 would be over 20 pounds of 
laterite!  At Duplas price of $50 per pound that would be a chunk of 
change.  I did this in a 230 gallon tank (used about 35# of laterite) but 
that is the subject for another posting.

So much for now.  Go ahead you entrepenuers (never could spell), go 
ahead and save everybody the inconvenience of having to get a minimum 
order from the souce.

Laterite balls/shards: low surface area

by Charley Bay <>
Date: Mon, 21 Aug 95

Earle Hamilton <> wrote:
> [snip, really good laterite overview]  
> Dupla sells the powder and 
> "pellets".  At one time the fellow who is the potter and I talked about 
> marketing this stuff and would have mixed up a batch of clay and run it 
> through the extruder he has.  We would then cut off hunks similar to 
> Dupla that would be about the size of a marble.  FIRING THESE CHUNKS 
> WOULD DEFEAT THE PURPOSE OF THE LATERITE.  It has been suggested we could 
> get laterite in our tanks by breaking up clay pots.  The stuff used for 
> clay pots has very little iron and I suspect firing bonds the stuff 
> together in a way that would be of little use to plants.
> I have seen no evidence that the clay chunks are of any real value.  They 
> do hold up well and are easy to form from the powdered laterite from 
> Duply or A.R.T.  If you work with this stuff you will find it takes very 
> little water and that the result is very sticky goo but it is easy to 
> make up the marbles.  Would be a great project for a fish club.

I just got back from 2 weeks away, and just reviewed this discussion.  I
will put in my two cents and let the thread die (I guess it seems to be

I don't understand ANY benefit to fired clay (other than it can provide
the same benefits that a gravel substrate may provide).  Having been 
fired at 1100+F, the iron is lost.  Even if it were there, virtually all 
of it is inaccessible because we now have a "stone" with a very LOW
surface area/volume ratio.

Back in my undergraduate studies in Soils, a very tremendous attribute
of all clays were their VERY HIGH surface area/volume ratio.  We are
talking hundreds or thousands of times higher than that we can observe
in sands or silts.  Those little flat platelets have tremendous surface
area with (often) a high CEC, and can tightly bond to each other.  This
is why clay holds its shape, and is why clay pots (fired or not) hold 
water.  Those really big H20 molecules just can't squeeze between two
platelets trying to grab cations off each other.  However, this tight 
bonding between clay particles also implies a clay material can quickly
go anaerobic because circulation is very difficult to achieve (although
heat coils seem to achieve circulation through convection through a short 
depth: a few inches of gravel and clay mix).

Thus, while non-fired clay balls may have iron available, we must get
a root hair in there to exchange those cations.  Because the ball is not
fired, the roots can (eventually) penetrate the mass (possibly dying if
it goes too deep, if it cannot get sufficient oxygen for respiration).

This is one reason why I think I like vermiculite:  A clay with a high
CEC, but "puffed up" into static structures (like puffed rice) that
inherently allow for circulation and CEC exchange.  I just have to
figure out how to "charge it" with iron and other macro- and micro-
nutrients, because it comes essentially sterile (it was fired in
its "puff-up" preparation, and to give gardeners a medium free from
possible parasites/bacteria/virii).

It seems much simpler to distribute the laterite around the substrate
in its smallest (manageable) form:  More surface area is *readily*
available to rootlets, it is more distributed so more rootlets can be
accommodated over the same cubic inch of substrate, and circulation
is (potentially) improved at the actual rootlet bonding site.

Of course, laterite in the form of "talcum powder" will compact more
over time and possibly find itself much more easily into the general
aquarium water body.  My guess is that if we are going to use laterite,
the most efficient leveraging of its CEC capacity and iron (and other
nutrients) would the smallest particle that would not easily be 
suspended in the aquarium, possibly going larger if we want a lot of 
lee-way when up-rooting our vegetation.  Something BB sized 
(say, 2-4 mm) seems appropriate.

I'm not sure how well it weathers over time, though.  If you start
with 2" balls of laterite and a year later you have a 6"x1/4" patty
of clay (to be extreme), then maybe larger is OK:  we will get the
surface area simply because time will make it so.

- --charley          or

A discussion of substrate additives

Date: Tue, 22 Aug 95

I have been procrastinating on preparing this article for a while
but now seems like a good time. I want to cover some of the technical
aspects of substrate additives with a view to explaining the 
popular theories about why they work. I will be borrowing heavily
from ideas presented by Jim Kelly in an article posted on September
of 1994 on sci.aquaria. Jim did research from a lot of sources but
credits  N. C. Brady's book, "The Nature and Properties of Soil" as 
his favourite. I want to keep this as appropriate to the general
audience as I can. Please feel free to correct me on any points of
error or if you just want to beg to differ! ;-)

Plant nutrients in solution are generally in the form of ions. When
a mineral salt dissolves in water, it separates into two ions: a
positively charged cation and a negatively charged anion. When a
salt dissolves, we call it dissociation which means the salt molecule
is split into two very mobile ions. Not all substances which can
dissolve or mix with water dissociate; for example, alcohols. I think
that EDTA and DPTA chelated minerals are examples of this. A chelated
mineral is a compound composed of an organic acid ion and a mineral
ion such as Fe or Mg. These complex organic acids are actually the
evolved mechanisms by which plants are able to capture and transport
components used in their metabolic processes including the conversion
of water and CO2 to simple sugars (photosynthesis!).

Horst & Kipper (of Dupla fame) did a lot of pioneering research into
aquatic soils and the value of light and CO2. An excellent book which
covers many of their findings applied to create a formula approach to
successful aquarium keeping is called "The Optimum Aquarium". They
measured nutrient concentrations in the natural habitats of aquatic
plants (esp. cryptocorynes) and conducted several comparative experiments
to evaluate techniques. They found that plants grown in a substrate
containing an iron rich tropical clay (laterite) grew much better
than plants grown in conventional sand and gravel substrates. They
also found that several other factors such as light intensity, the
concentration of dissolved CO2, the concentration of ammonium (nitrogen),
and other critical micronutrients such as free iron, magnesium etc.
were even more important to high growth rates of plants.

Horst & Kipper theorized that iron from laterite subsoils was being
leached into the mineral rich springs which feed the Cryptocoryne
habitat. To date, no one has been successful at duplicating this leaching
process in an aquarium to the extent that it provides sufficient iron
to satisfy our plants requirements. We rely upon chelated nutrient mixes
which H&K also pioneered to supplement what is available from the tap
water. Given that one uses these supplements, the value of the iron
in laterite is uncertain. How can we explain the obvious success of
tanks using the Dupla laterite method? Laterite and other substances
possess another property called the Cation Exchange Capacity (CEC).
Remember that several of the important nutrients for plant growth
including ammonium, iron, potassium, phosphorous and magnesium can
exist in solution as cations! (or sometimes in combination with oxygen 
as anions)

Clays, humus and finely powdered mineral oxides have varying amounts
of CEC. The ultra fine particles of clays are tiny crytals of oxides
and silicates usu. of iron and aluminum. These crystals are in effect
giant molecular structures and the edges of these crystals possess
negative charges. Positively charged cations are attracted to these
sites where they form weak molecular (electrostatic) bonds. Since these
ions are not bound tightly, they can be displaced by other ions in the
solution esp. by thermal agitation. CEC quantitatively measures how
many cations can be captured by any given substance. Here is a table
given by Jim Kelly:

          Soil Component           CEC (cmol/kg)
          --------------           -------------
          humus                    200
          vermiculite              150
          smectites                100
          illite                   30
          chlorite                 30
          kaolinite                8
          Fe, Al oxides            4

Substrates with CEC help plants to capture and absorb important nutrients
with their roots. Plant roots secrete organic, humic acids (found in 
humus) which are able to displace the nutrient cations, bind them
into soluble chelates and make them available for absorption into
the root where they are transported to the leaves for use by the plant.

Laterite is comprised of Fe and Al oxides and kaolinite-like clays
which contribute little to the CEC of the substrate. Jim mentions other
amorphous minerals of volcanic origin (presumed in laterite) which
have high CEC and may contribute to laterite's CEC. In addition,
the hydrous oxides of Fe & Al in laterite can have anion exchange
sites which may be important for phosphate ions. Jim didn't talk much
about anion exchange or how important it is relatively. He did talk
about the possible benefit of iron oxides in reducing phosphate
concentration by attracting these anions and making them chemically
unavailable. The iron oxide needn't be in laterite to perform this
function but should be in the substrate if there is some degree of
substrate circulation.

"HUMUS is the end product of the decomposition of organic matter.
It is a complex substance consisting of material either modified
from dead plant tissue or synthesized by soil organisms.  It is
fairly resistant to furthur decay (in contrast to peat moss, which
is relatively undecayed organic matter but which also has a high
CEC) and thus forms the long-lived organic component of the 
substrate (but not as stable a clay).  It has the following
characteristics:  high surface area per volume, exceeding clay
particles; has negatively charged carboxylic and phenolic sites;
has an entirely pH-dependent CEC, which is low at low pH but 
exceeds silicate clays above about pH=6;  when saturated with H+
ions in its exchange sites it can extract nutrient ions (e.g. Ca,
Mg, K) from minerals by dissolving them, and then hold the 
nutrients in exchangeable positions for plant uptake." (Jim's words)
It has excellent nutrient exchange properties.

Humus, laterite and clay all have one undesirable characteristic;
their fine structure makes them subject to compaction and may prevent
the diffusion of water and oxygen into the substrate. Plant roots
themselves can assist in providing oxygen. Vermiculite and sand
are good additives to help prevent this compaction and allow the
roots to penetrate. Many aquarists use heating coils or very slow 
reverse undergravel flow to provide the very low levels of oxygen
and water/nutrient circulation. This does not appear to be necessary
with the use of vermiculite in a low organic substrate.

High organic substrates such as peat moss or commercial potting soil
mixtures are NOT good. There is far too much undecomposed organic
material which will rot in the low oxygen environment producing
toxic sulphide gases. Jim Kelly recommends loam, straight out of your
garden. I'm using commercial humus from earthworm castings. This is
mixed with a larger proportion of vermiculite which has been allowed
to saturate with water and used in the lower layer of the substrate.
The top layer consists of coarse sand or fine gravel (2mm dia).

This is by no means a complete discussion of all aquatic soil properties
but it is long for a posting. I've tried to keep this understandable.
I hope it clears up some of the confusion between chelation of metal
ions and the cation exchange process. I hope it takes some of the
mystique out of laterite and iron oxide clays and encourages people to
try out some new ideas! I also hope Jim has time (and interest) to
share some of his latest findings along with his recipe for vermiculite-
loam substrates.

 - Steve

"other" laterite substrates

Date: Fri, 1 Sep 95

> Anyway, I just want to add my .02 to the "holy war" :), and make it clear 
> to people just starting out that if you are confused about what substrate
> to use for your first plant tank, laterite is a less risky bet than 
> vermiculite, especially if you follow Earl's suggestion to obtain cheap 
> laterite by the pound.

Oh-NO!! That's the point of the discussion here. Duplarit-G is granules;
that's why it doesn't impede circulation. Even if you made pottery clay
into granules and dried and baked it, it would very rapidly revert to
the powder form in the substrate. If you kiln fired it, it would change
it's chemical properties and it definitely would not contain the porosity
of lava originated crushed rock. IMHO, using large amounts of this stuff
would produce a very dense substrate. For beginners not concerned overly
with the cost I would recommend the "Optimum Aquarium" method which
is designed to easily reproduce good results. If you want to save money
on laterite and heating coils, I would recommend vermiculite in the bottom
layer and a top layer of plain #1-3 gravel. I consider the use of peat
and soil mixtures the experimental stuff. An acceptable alternative to
Duplarit at the high end is Terralit. The stuff is incredibly expensive

Hot Gravel & Laterite source

by Earle Hamilton <>
Date: Tue, 15 Aug 1995

Source for laterite --- When I discovered this source I saw it as an 
opportunity to make a buck but since I have a wonderful young wife who works 
and makes big bucks (I don't need the money) and since I'm retired, I 
decided not to go commercial.  Laterite is available in 50 pound bags for 
about $10.  It is used by potters to make clay pots.  It is similar to 
terra cotta but not the same.  Most potters don't even know they are 
working with laterite but I happened to stumble on one who knew fish  and 
pottery who gave me a 5 gallon bucket of the stuff.  It looks exactly 
like the Dupla stuff.  Skeptics will challenge the chemical composition 
difference but I won't accept the challenge - Im lazy.  Not so different 
than using sand blasing grit at cent per pound vs mail order packaged 
stuff and many times the cost. 

Laterite clouding and 230g update

by Earle Hamilton <>
Date: Tue, 5 Sep 1995

A little slow in talking about this even though there were several posts 
re clouding (Thanks, Phillip).  
Case 1.  Not having the benefit of this list and the access to "The 
George" (Boothe) - I thought a good way to get laterite into the 
substrate was to mix it with the bottom 1/3 gravel and put it over an UG 
filter plate.  I used Dupla powder laterite in a 100 gal tank.  Instant 
mud!  It looked like one of those high silt river runnoffs with initail 
visibility of about 1"  After a week it was closer to 8" of visibility so 
it was obvious the tiny clay particles were attatching themselves 
somewhere.  In a few weeks the tank was crystal clear.  Gravel vacuuming 
always showed evidence of laterite in the vacuumed gravel.  BTW - tank 
had MH lites and Dupla co2.  Great plant growth.
Case 2.  Wife let me get 230 gal so I tore down the 100 and set 230 in 
same spot. (72x24x30hi inches).  Since setting up the original tank I had 
the benefit of reading G. Boothe's article in AFM re substrate heating 
advantages and why ugf is no good with laterite.  Also had built a few 
DIY UGHeater systems.  So the 230 was set up with 1/2 of the tank with 
ugheater and laterite.  Other half was ugf with 230 gph power heads (2 
plates and power heads).  Due to a missunderstanding in reading TOA, I 
used about 10x the recommended amount of laterite.  This was the cheap 
pottery stuff described in previous posts.  The laterite was mixed with 
wet gravel and the resultant bottom layer of substrate looked fairly 
dry.  I carefully added non treated gravel over the filter plates and 
then very slowly filled the tank. 
When using a gravel vacuum I like to go deep - all the way to the 
I placed a piece of egg crate light diffuser grid over the laterite rich 
bottom to protect the laterite from being sucked up in vacuuming.
When the power heads were turned on they immediately spewed forth clouds 
of laterite but not as bad as the case 1 tank.  Nuts - somehow the 
laterite had crept into the other side past the plexiglas barrier I had 
placed in the gravel.  At any rate the cloudiness dimminished fairly 
quick compared to the case 1 tank.  I was always able to see to the back 
of the tank although very cloudy.

Case 2.1 - - DISASTER  After being set up for 6 months the tank developed 
a leak.  AFM magazine came the day I discovered the leak and there was an 
excellent article on how to fix a leak.  Good timing.  At least I'm not 
the only one who ever had a leaky tank.

Teardown was time consuming but straight forward.  The grid allowed me to 
strip off all the regular gravel and save the laterite gravel without any 

Interesting observations- - the plants did very well on both sides of the 
barrier but some val  grew noticeably faster on the laterite side.  The 
ugh was on very little due to the warm weather.  On teardown the ugf side 
had considerable laterite in the gravel.  When I washed the gravel it had 
the rusty mud color.  Also, the bottom of the filter plates were stained 
with clay that had been in suspension and then adhered to the plate.

Roots had penetrated all the way under the filter plates and  in a few 
cases on the laterite side there were roots deep into the substrate.  The 
substrate looked very dense with so much clay but there was no obvious 
organic material or smell etc to indicate anerobic status.

Case 3.  Finally got the tank set up yesterday with slight differences 
from the original.  The clay rich section was less moist.  When clay 
sticks to gravel and is not disturbed, it tends to stay put.  The tank 
was filled and when the ugf power heads were turned on there was almost 
no cloudiness.  After 36 hours of operation the tank is crystal clear.  
Forgot to mention the gravel is about 6" deep so the roots going all the 
way to the bottom of the tank raises a question of just how far they 
would go if left to a bottomless base.  Hopefully the laterite migration 
into the ugf side will be nil and that we can see a more significant 
difference between the two sides.  The earlier pass with the large amount 
of laterite in the ugf side indicates the laterite was available to both 
sides so it is not surprising there was little difference.

Hopefully the tank will not leak and we will have enough time to report 
significant diffrences at some future time.  The conclusion I would reach 
at this point is that laterite will cloud a tank if too much water is 
used when mixing it in the gravel.  The less the better.  And even if it 
does get into suspension it will eventually clear by adhereing to 
everything it comes in contact with.

Sorry for the long post but hope this will be of interest to some of you 
out there.

Laterite and ugf

by Earle Hamilton <>
Date: Tue, 5 Sep 1995

One thing I forgot in the previous post.  With the experience of having 
the case 1 tank clear up in time we experimented and dropped a tablespoon 
of laterite powder into the tank.  Not surprisingly it became clouded 
very quickly as the laterite dispersed.  But within 24 hours the tank was 
clear again.  I think it was Dave G. who suggested this would not work 
but I think you will be surprised at how temporary the clouding is.  It 
could well be that dosing a tank every couple of months would put enough 
laterite through the substrate to do some good.
Gads there are lots of variables to mess with if you want to get 
experimental about things.  Problem with most of these "experiments" is 
that information is interesting but not conclusive due to lack of 
complete measurements and more importatly a lack of control tank.  But 
that won't stop most of us.  A word of caution though - - don't take any 
of these results as Gospel.  With over 300 variables that can be 
measured, even the control tank would be less than perfect.  


by Tyson Lee <>
Date: Wed, 3 Jan 1996

Thanks for the reply.  I rolled some small pieces into balls and I am 
letting them dry out a bit before I try to place them under some roots in 
my tanks.  I just hope that it does not cloud the water too bad.  Then 
again, when I stir up the gravel, even my expensive Dupla balls does this.

Take care and I always enjoy your posts. (especially since I got the 
CO2/plant bug) :)

Tyson Lee

Price of laterite at Laguna Clay

by gtong-at-SIRIUS.COM (G.Tong)
Date: Mon, 25 Sep 1995

I just noticed that my message about laterite from Laguna Clay got a little
mangled when converted to ascii. Here's the info again:

A.R.T. (ask for Chuck)
1-800-323-0212; in Illinois somewhere
5#/$3, 50#/$11
Minimum order is $30 or there is a $5 handling charge.
Shipping by UPS extra.

Laguna Clay
1-800-4-LAGUNA; in City of Industry, CA
33 cents/lb
Minimum order is 1 pound.
$2.50 handling charge for UPS orders.
Shipping by UPS extra.

Greg. Tong
San Francisco, CA, USA

"Every infinity is composed of only two halves."

Soil Substrate

by mccarten/ (niall mccarten)
Date: Sat, 1 Mar 1997

First, there are different types of laterites which are leached aluminum,
iron, and other mineral silicate oxide soils. Laterites are very uncommon in
North America. Because laterites are formed in tropical climates any
laterites in North America are exhumed ancient soils from a time when the
soils were in a tropical latitude. Aluminum laterites, such as bauxite,
found in Arkansas and some other southeastern states, and the Carribean are
the source of aluminum foil.  In California, some alumina laterites are
associted with very pure kaolinite and are mined for pottery.  These
aluminum laterites contain little iron.  Iron laterites are also uncommon
and do not occur in pure forms in the US to my knowledge.  Laterites from
the tropics would be a better source to ensure you are getting laterite.

Second, all the sources of these laterites are soils which are a mixture of
minerals, salts, and organic compounds including various amounts of
nitrates, phosphates, and a host of other macro- and micro- nutrients.

Using soil surveys, such as the USDA Soil Surveys prepared by the Soil
Conservation Service (now called the National Resource Conservation Service)
for many counties and parishes in the US, one might find areas of oxidized
soils, but the mapping covers broad areas and the site you pick will
certainly not be "pure" laterite.  The way soils are described and mapped
may not even indicate whether or not it is a laterite.  A complete chemical
soil analysis to determine quantities of all the eliments that need testing
will probably cost in excess of $100 per sample!

I suggest that before polluting ones aquarium with soil of unknown
composition you think twice.  If you believe laterite is what you want then
commercially available sources in the aquarium industry may be the source
since they are probably from a tropical source.  Since you probably want
iron laterite and not aluminum laterite it is another reason to question the
source. Just because the soil is red does not mean that it is pure iron
laterite or even laterite.  There are many red oxidized soils containing
iron that are not laterites.  Also, if you insist on using laterite or
something from the ground, wash it continuously with distilled or deionized
water for a long time to get rid of some of the available nitrates and
phosphates. The iron mineral will sink in the water since it through an
equilibrioum reaction with iron mineral and the aquarium water that the iron
ions will become available to the plants.

Good luck,

Niall McCarten, Ph.D.
Plant Ecologist
UC Herbarium
Valley Life Sciences Building
Berkeley, CA

Re- Laterite "Mined in the

by "Mark Shelton" <mark_shelton/>
Date: 9 Mar 1997

>From: Linda or Jim Lemke <>
>Date: Thu, 6 Mar 1997 22:33:04 -0600
>Subject: Laterite "Mined in the USA"
>Back to Laterite again.  I just read the back of a jar of Thiel Aqua
>Tech's "Laterite" (UPC 60100) and to my amazement on the back label it >said
"Mined in the USA". I don't recall it it said anything about iron >(certainly
I wouldn't think it would mention aluminun). So this still >doesn't prove that
there is laterite in the US similar to tropical >laterite. So where is this
>Jim Lemke

    I forwarded the above post to Albert Thiel, his response follows:

Thank you for your message on laterite and for posting the web site address
to the newsgroup. I appreciate it.

Laterite from the Tropics is expensive as we know, so years ago I started
talking to mining companies to find out if we could find a similar product
here. I sent samples to several of them to make sure they knew what I was
talking about.

It took quite some time for many of them to do anything about it because (I
guess) they did not really see a big market for this product.

After receiving samples from several companies and running tests on these
samples we settled on a product mined in Arizona that seemed to contain the
minerals and the iron we are so interested in for our plants and have been
selling that variety for quite some time now with great success.

Plants do real well and replacement is not necessary in the short run. The
variety we have seems to release nutrients for the plants over the long
run.That does not mean though that additional supplementation with Plant
Nutrients is not necessary. Laterite or Elaterite as some mining companies
called it, provides nutrients but not in sufficient amounts in tanks with
large amounts of plants rapidly enough. It is necessary but the release of
nutrients at the root level is slow. In tanks with lots of plants this
requires using addl nutrition so it is more rapidly available. Sort of a two
prong approach: root and supplementation.

Yes the Laterite we sell contains iron and I should probably add that to the
label to make that clear. That is my fault, I guess I assumed that one would
automatically infer that it did because it is laterite. I will change the
label when we produce new ones to reflect this.

I hope this answers your questions and if it does not and you need more
info, please feel free to ask more questions. You are welcome of course to
repost my answer.

Albert Thiel
3/9/97  07:44

FWIW, Mark.

processing laterite

by George Booth <booth/>
Date: Thu, 15 Jan 1998

>From: "Shimoda, Wade" <>
>Subject: How is laterite prepared before it is sold?
>I would like to know if companies such as Dupla prepare the laterite
>before packaging it.  

I don't know the specific steps, but I sure it's cleaned of excess organic crud, 
dried and pulverized to a specific fineness. 

>I am wondering if the packaged stuff is somehow
>treated to reduce clouding of the water with the particles of clay.  

No, if it is added to the water directly, the water will cloud up.  That's why 
it is mixed with the bottom 1/3 of the gravel and then covered with clean gravel 
- -- to seal it in.  Dupla laterite settles out quickly if some is pulled up with 
a plant stem but will make a mess if it's not "sealed".  I once reused some 
gravel with laterite.  After washing it as much as I could stand, I put it back 
in the tank and did not use clean gravel to cover it.  The water was red for 


Fe2+ / Fe3+ [long but hopefully interesting]

by Neil Frank <nfrank/>
Date: Thu, 23 Apr 1998

>> On George's Aquatic Concepts web pages now found 
>> [here] he discusses
>> several of the functions of heating coils. He says that [heating coils]
>> "Provide warmth in the substrate to speed up biochemical processes." 
>> [snip] 
>> I told Neil Frank I thought heating coils might be helping provide iron
>> in George's laterite substrates and he countered: "I don't buy this....
>> maybe he can test it out by not using his daily dupla drops which is
>> essentially only iron." This is a reasonable experiment and maybe George
>> could try it for a few weeks.
>Oh, sure, not adding Dupla drops for a few weeks is VERY reasonable.  Let
me run 
>right home and start killing my plants. Good idea Neil. Note the lack of a 

I actually was smiling to myself when I told Steve (in an off-line
conversation) that you might do such an experiment. BTW, this out of
context statement was responding to Steve's assertion that heat coils were
the ONLY source of iron to all plants.

>To my fevered brain, and as clearly stated on my website, the heating
coils are 
>MAINLY there to create circulation currents which pull the chelated iron
>the water column into the substrate where it is bound by the sufficiently
>CEC of the laterite until it can be adsorbed by plant roots.  If the warmer 
>substrate helps with other chemical processes or with delicate plants,
that's a 
>bonus not a design goal. 

IMHO, the role of the laterite together with heating coils is NOT to bring
iron to substrate (it is already there!), but instead to circulate water
and chemically bind phosphates. This is one of the important advantages of
ALL iron-bearing substrate materials. This helps to keep phosphates low in
the water column to starve algae. BTW, this concept is now mentioned in
DUPLA's publications.

>I have no doubt that the laterite provides lots of iron initially (the first 
>month or so after setup).  I typically measure iron levels in the water of
>mg/l or more right off the bat.  After the tank is established, I only see
>levels corresponding to the addition of drops. I once measured iron levels
>after a particularly brutal uprooting and pruning where the water was
>red for a few hours. No spike in iron concentration as I would have
suspected. I 
>think there is some available iron in laterite but most is "locked up for
>in strong bonds with other minerals (of course, that's purely conjecture).  

Yes, it appears that the iron from the laterite is kept out of the water
column... except during initial setup and other disruptions of the substrate.

I agree with George that laterite can be a source of iron to plants with
roots. However, laterite/latersoils CAN be a source of iron to ROOTED
plants, but only UNTIL the substrate becomes root bound or otherwise too
aerobic (from O2 thru the roots). Then the substrate iron cannot be reduced
and be generally available to plants. Presumably some (but perhaps not all)
 plants can overcome this with humic acids from roots (acting the same as a
chelator). In either case, I agree with George that the plants need roots
to make this happen.... not relevant for recently cut stem plants or
unestablished rooted plants. For these, iron in the watercolumn will help
to keep the plants reestablishing and growing.

>I think the long term purpose of laterite in the substrate is to act as a 
>bonding site for nutrients brought into the substrate by whatever
circulation is 

Yes... mostly P. I have not seen anything written to mention any other

Neil Frank, AGA

Laterite, Arcillite?!

by "A. Inniss" <andrewi/>
Date: Mon, 30 Mar 1998

	While poking around in a local garden supply shop in my home town
in Canada, I came across a new product which sounds like yet another
laterite-like clay.  Put out by Profile, it is:

"A Natural Mineral Blend that has been kiln fired [...] will last year
after year [...] contains thousands of internal and external pore spaces
[...] holds on to precious plant nutrients and exchanges them directly
with plant roots, increasing the eficiency and benefits of your plant
fertilizer [...] is not a chemical or fertilizer, is not toxic, and has no
effect on pH [...] provides a haven for valuable microorganisms that
normally are filtered out and provides a suitable environment for fish to
lay eggs."

	At $14.99CDN for a bag probably a bit larger than a bag of
Flourite ($24.98US), it looks interesting.  What it is saying in its
advertizing, I gather, is that it has a good CEC and so on.  Sounds like
another "laterite substitute." Supposedly it merely needs to be submerged
and saturated, and then will not float or break down.
	PROFILE Professional Aquatic Plant Soil is 100% Arcillite, a
substance I wasn't able to find in any of what meager resources I had
immediately at hand.  Any soil scientists care to comment on Arcillite?  I
wasn't able to see it or get an idea of its grain size, unfortunately, as
the nature of the bag its in precludes that.
	I don't have any place to experiment with it at the moment, but
perhaps one of you might give it a whirl and report back.


Laterite, Arcillite?!

by Beverly Erlebacher <bae/>
Date: Tue, 31 Mar 1998

> Date: Mon, 30 Mar 1998 21:45:44 -0800 (PST)
> From: "A. Inniss" <>
> 	While poking around in a local garden supply shop in my home town
> in Canada, I came across a new product which sounds like yet another
> laterite-like clay.  Put out by Profile, it is:
> "A Natural Mineral Blend that has been kiln fired [...] will last year
> after year [...] contains thousands of internal and external pore spaces
> [...] holds on to precious plant nutrients and exchanges them directly
> with plant roots, increasing the eficiency and benefits of your plant
> fertilizer [...] is not a chemical or fertilizer, is not toxic, and has no
> effect on pH [...] provides a haven for valuable microorganisms that
> normally are filtered out and provides a suitable environment for fish to
> lay eggs."
> 	At $14.99CDN for a bag probably a bit larger than a bag of
> Flourite ($24.98US), it looks interesting.  What it is saying in its
> advertizing, I gather, is that it has a good CEC and so on.  Sounds like
> another "laterite substitute." Supposedly it merely needs to be submerged
> and saturated, and then will not float or break down.
> 	PROFILE Professional Aquatic Plant Soil is 100% Arcillite, a
> substance I wasn't able to find in any of what meager resources I had
> immediately at hand.  Any soil scientists care to comment on Arcillite?  I
> wasn't able to see it or get an idea of its grain size, unfortunately, as
> the nature of the bag its in precludes that.
> 	I don't have any place to experiment with it at the moment, but
> perhaps one of you might give it a whirl and report back.

Arcillite is a calcined montmorillonite clay.  According to a U of Florida
web page (

	There are now a number of companies in the United States which quarry
	clay and heat it in specialized kilns which cause the clay to expand
	under high temperature into a highly porous fused structure which is
	physically and chemically stable. The next steps involve crushing large
	chunks of calcined clay into smaller particles which are subsequently
	graded into specific particle size ranges. Light weight concrete
	products and road surfacing additives are two popular applications.

(Stuff about use in high-traffic turf areas, potting soil mixtures snipped)

	Many calcined clays have properties which make them desirable as
	potting media components. Those clays which are receiving the most
	attention are more porous and therefore considerably lighter in weight
	than Turface. Calcined clays are essentially indestructible particles,
	which provide non-capillary pore space to a mix due to the large spaces
	created between particles, and hold water internally within their
	open-pore particle structure. Most calcined clays have good cation
	exchange capacity which helps in the retention of nutrients but have no
	nutrient value of their own.

The last time I looked into this, I was looking for info about Turface, 
which is a similar product with a nice terra cotta color and a texture
somewhat like kitty litter.  It retains its shape when wet, unlike kitty
litter, and is softer than crushed brick or crushed terra cotta flower
pots.  I ran into a web page for Profile which I can't find now.  I did
run into a reference to use as a soil amendment for turfgrass, so I assume
it is similar to Turface in its physical and chemical properties.  I seem
to remember that it was formed into small cylinders, rather than the random
crumbles of Turface.

Turface is much beloved of bonsai, cacti and alpine plant enthusiasts.
A powder form is available for drying out muddy athletic fields before 
a game.  It's heavier than most soil amendments like perlite and vermiculite,
which makes it more expensive due to shipping costs, but it's much lighter
than gravel.  It sinks easily and stays sunk.

At any rate, I've been wanting to use Turface as a substrate for some time,
but haven't been able to get a large bag of it.  I got a small sample bag,
and it is nice looking stuff, only slightly dusty.  Note that while these
calcined clays have good CEC, they have no nutrient value.  I wonder if the
pores are suitable for bacterial conversion of nitrate to nitrogen.

If anyone wants to try either of these products, it is probably cheaper
sold as a soil amendment than as a specialized aquatic plant soil.

Btw, the distributor for Turface in Canada is Plant Products, Ltd. in
Brampton, Ont.  I think this is the same company Sears and Conlin got
their lifetime supply of trace elements from.


by Steve Garinger <sgaringer/>
Date: Thu, 14 May 1998

>Question 1:  This evening I put some "Redneck Laterite" in the
substrate.  I used to live in Huntsville, AL and had a friend send me up
a couple of lbs of the reddest clay rich dirt he could find.  I smushed
them into 1" balls and tucked them in the substrate near the base of my
plants.  Will this help my plants?  I refuse to believe that Laterite is
the only way to go.
I am also a former Huntsvillian, and I have used the clay to good
effect.  I found some dark red, exposed clay and bagged up a few pounds
on my last visit.  It may actually be laterite; I can't say for sure,
but I can say that I can find the balls I have pressed into the
substrate by letting the dwarf sags run wild for about two months and
noting where the largest colonies form.  Invariably when I pull them out
there is a red cloud. 

The first time I used it, I was concerned about it fogging up the tank,
and the fact that there were some roots in it.  So I boiled it.  I got a
large amount of rust-red water, the clay broke into tiny pieces, and the
roots floated out.  Then I, after letting it cool, made it into balls
and dried it before putting it in the tank.  I am bolder now, and just
break off a small chunk now and then when I see a plant that is slowing
down.  I have not had any trouble with it staying in suspension when it
is stirred up.  The red cloud that comes with uprooting a plant
dissipates in 5 minutes or less. 

Two caveats: 1) The location your friend got it from is most likely not
the one I got mine from.  So you could have different soil, or it could
be contaminated with some of the rich brew of chemicals cotton growers
are so fond of.  Be cautious.
2) As with everything else, moderation is the key.  (Excuse me while I
step up onto this soap box...  Thanks.) Too many of the people here,
especially beginners, seem to want a tank where the plants grow so fast
they'll blow the top right off the aquarium, and they want it NOW!!! 
Usually it is the algae that will do this.  Take things slow, especially
in the fertilizer area, and I suspect you will have a stable tank
faster.  (Stepping down now.)

Steve Garinger

Substrate, Laterite

by Roxanne Bittman <rbittman/>
Date: Thu, 9 Apr 1998

Wade S. asked whether it was possible to use too much laterite; or, put another 
way, is more better?

Thought I'd relate a little experiment which is still ongoing:
A friend of mine set up two 20g high tanks in identical ways except for the 
substrate.  One had the recommended amount of Duplarit G added to the lower 
third of the gravel.  The other had 2-3 times as much of Duplarit (G and K) 
added (combo of the ground laterite and the balls).

The two tanks have matured in dramatically different ways.
The one with the extra laterite has had a great deal of algae (different types 
of green algae mostly) and the other tank has had almost no algae.

The experiment is not quite finished; more to come.  Take note however and be 
warned of "over-laterization" of your substrate.

As an aside, I have had tanks with great plant growth both with and without 
substrate additives.  My current tanks have the rec. amt of Duplarit G in the 
gravel.  My one experiment with more stuff in the gravel (peat, dirt) was 

Roxanne Bittman

Iron and substrates

by krandall/
Date: Sat, 28 Nov 1998

Bob Dixon wrote:

>So what percentage of iron content is necessary in a substrate additive like
>laterite or other clay if one wants to maintain a tank without teardown over
>an extended period of time, say foive or six years?  I realise this is
>conditional on the size of the tank, the amount of substrate additive, the
>types and quantities of plants, etc, etc, ad infinitum, but can someone
>generalize on an average tank of a nominal size, say 55 gallons, or maybe 100
>gallons with a given substrate additive level as recommended by say, Dupla
>(wouldn't that be like 10 g. per gallon, mixed into a one inch layer at the
>bottom of the substrate)?

I've said this before, and I'll say it again.  I have _never_ had a
laterite based substrate of _any_ size "give out".  I have had tanks
running as long as 8 years.  Those with shorter life spans have been taken
down for moving or changes of tank size, etc., never because I felt they
had "given out".  I use laterite in the amounts recommended by the
manufacturer.  You don't need huge amounts to do the job.

>And has anyone actually tested the iron content in their substrate additive
>before setup and again after a couple years, in order to demonstrate that
>is indeed coming out of the clay?  Or are we all assuming that the iron thing
>Dupla has sold us on is actually happening?

Dupla recommends regular supplementation with iron.  I know it is possible
(through neglect<g>) for plants in laterite based tanks to become iron
deficient if they do not receive periodic supplementation.  Likewise, it
has been my experience that JUST using liquid supplementation in a tank w/o
laterite doesn't do the job for most root-feeding plants.  So whether the
mechanism is what Dupla thinks it is, or whether something different is
going on, I won't even guess at.  The fact of the matter is, the system works.

>Some folks, I think Karen is among them are not using substrate coils.  Do
>these tanks deteriorate after a given percentage of substrate iron is
>depleted?  Or do the keepers of these tanks simply recognize iron deficiency
>symptoms and suplement into the water column successfully?

As I said, I've never seen any substrate deteriorate to the point of being
unusable.  I think _most_ substrates require the addition of supplemental
trace elements from time to time, although it may take longer for some to
need this than others.  Even Steve P., who is a strong proponent of soil
substrates as a means of providing most nutrients for his plants admits to
at least occasional supplementation.<g>

As far as cables are concerned, I have had limited experience with them,
and none with commercially made systems.  I do know that in a heavily
planted tank with good growth, the plants themselves draw water down into
the substrate.  (actually, they draw water OUT of the substrate and into
their tissues, which is then replaced from the water column above)  This
process certainly seems to be adequate for excellent growth.  I'm not in a
position to say it couldn't be BETTER with cables, but it can be very, very
good without.

The only substrates that I have heard of that have actually "gone bad" have
been poorly designed to start with, (too much clay or too much organic
material) and/or in tanks without adequate root penetration, i.e. tanks
that are not heavily planted and growing well.

Karen Randall
Aquatic Gardeners Association

Laterite and clay

by "Roger S. Miller" <rgrmill/>
Date: Sun, 24 Jan 1999

On Sun, 24 Jan 1999, Bob Dixon wrote:

> I thought laterite WAS
> clay.  That's why kitty litter works as a good (to some folks anyway)
> substitute.  It definitely IS clay, at least the cheap, no-clump, no-deodorant
> stuff we are supposed to be using is.
> So set me straight here, okay?  Thanks

Laterite is a heavily leached tropical subsoil.  When exposed and dried it
sometimes is rock-like.  It isn't a fertile soil.  Laterite consists
usually of aluminum oxyhydroxides with smaller amounts of iron
oxyhydroxides and a little bit of a clay mineral called halloysite.
Silica, calcium, magnesium, potassium and sodium are present in very low
amounts or absent.  In some instance the iron content of laterite can
exceed the aluminum content, but even small amounts of iron will tint the
laterite rust red.  Phosphate has a strong tendency to attach to the iron
hydroxides present in most laterites.  The laterite may have a small
cation or anion exchange capacity, but I don't think this is an inherent
property of the material.

The material marketed as laterite may or may not be real laterite but I
suspect that most of it actually is laterite.

Clay may refer to any very fine-grained soil.  Clay soils are made up
mostly of a group of very finely crystalline minerals (grain size
typically << 2 microns) that are collectively called clay minerals.  There
are also varying amounts of organic materials, iron and aluminum
hydroxides and silica. A clay used for ceramic work is composed largely of
clay minerals.  Clay minerals are complex aluminosilicates with an
inherent cation exchange capacity. Most clays contain significant amounts
of iron, magnesium, calcium, potassium and sodium.

There are a several different clay minerals and a very large variation in
the properties of materials called "clay"

Roger Miller


by "Roger S. Miller" <rgrmill/>
Date: Fri, 5 Feb 1999

On Fri, 5 Feb 1999, Richard Sexton wrote:

> Ok, so whats the deal with this stuff? Is red potters clay good enough ?
> is kitty litter as good ? Does the brand of laterite make any difference ?

I remember long discussions comparing the relative merits of different
brands of laterite.  I've never used any of them, but I think the upshot
was that they aren't all the same; some people reported tenacious
red-water problems with non-dupla laterite.  I've had reasonable success
mixing small amounts of kitty litter in the lower part of a substrate, and
some spectacular localized effects from pushing it into a gravel substrate
near an Echinodorus amazonicus.  I haven't tried red art clay but I
suspect it would give better results than kitty litter, but would be much
more difficult to work with.

> The Dupla stuff was supposed to be from Malaysia as far as I know, will
> laterite from other countrues work ?

George Booth keeps repeating that it's from Sri Lanka.  I think he forgot
his other mantras, so he fell back on that one.

Laterite is fairly common in tropical zones so I see no reason why other
sources wouldn't work.  It wouldn't be quite as easy as ringing up Jaime
and having him dig some dirt out of his back yard in Honduras.  It sounds
like the material would have to be unusually high in iron (for laterite,
which is usually mostly aluminum minerals) and will need some
processing before it's useful.

> Is it feasable ship a great whack of the stuff (a few hundred pounds, say)
> to North America and then divide is up and send out small packages of it
> to needy poeple ? How much processing and of what kind does it need.

Laterite can be found in Central and South America; years ago I saw
samples of a laterite "rock" that an acquaintance brought back from
Guatamala where he'd been building wells for Indian villages in the
jungle.  It was quite red, but in the absence of an analysis, I'd guess
it's a lot of aluminum with just enough iron to give the color.  There
might even be sources in relatively import/export friendly Mexico.

There's even a laterite, or laterite-like soil, in Arkansas.  I believe
that its quite high in aluminum.  Maybe there are high-iron occurances in
the same area.

At a minimum, the stuff would have to be cleaned, probably crushed and
sieved, and dried.  Import/export regulations could put severe limitations
on shipping the stuff.  Also, if you're looking for raw material, then you
will need to specify (at least) composition, texture and moisture content
and quantity in considerable detail.

A friend of mine is an exploration geologist, who when last I checked was
looking for more things to explore for.  He was working in Costa Rica and
Honduras at the time and I think I might be able to get in touch with him.
O'course, he'd probably only help if there were $US to be made in the
deal, but he might know of someone who's already quarrying the stuff.

All in all, I suspect that aquarist's would be better off buying brands of
laterite that are already on the aquarium market.

Roger Miller

"Real" laterite

by "James Purchase" <jpurch/>
Date: Fri, 5 Feb 1999

Jennifer Glover is worried that she may be visited by the APD Police
Department and cited for using "fake" laterite -

>Now this may be another case of beginner's confusion, but isn't Substrate
Gold also
>laterite?  It just comes from the United States and not Malaysia, where
Dupla's comes
>from?  I know that I used Substrate Gold, and it looked like laterite!  Not
>scientific, but the web page for it says it is laterite and I even heard
about it
>from this list.  It is cheaper (probably because it is local and not from
around the
>world), has some extra enriching stuff in it, and as a plus, I know it
>introduce some nasty tropical bug into my local area.  (don't laugh, I
heard an
>internet rumor about a possible US import ban on dupla laterite, due to
some microbe
>found in some of the samples.  And we all listen to internet rumors,

Yes, yes, yes, yes, yes, yes, and no (I don't listen to internet rumours,
well, at least not any more...). The Substrate Gold you have in your
aquarium should work just as well as "genuine" Dupla laterite. It is
probably not the exact same mineral (as Roger Miller pointed out) but it
will be close enough for our purposes. As far as the importation of "nasty
tropical bugs", the US Dept. of Agriculture is very strict about that sort
of thing - soil is _not_ allowed to cross the U.S. border. That is the main
reason all of you Americans are denied access to Tropica aquarium plants (I
knew there was another good side to living in Canada). Dupla was required to
prove to the Department of Agriculture's satisfaction that Duplarit G was
free from any nematodes or other soil borne pests before it was allowed into
the country. I believe that at least one shipment was held at the border for
that reason.

Mr. Schroeler doesn't have that same constraint, so his product can be
cheaper (read as less expensive).

>I just want to be sure that I haven't accidently used some "fake" laterite.
I am
>really trying to follow the ideas expressed by Horst and Kipper, in the
>Aquarium, but I didn't necessarly want to buy their products.  It is all
about money,
>like most things in life.

The principles outlined by Horst and Kipper in The Optimum Aquarium are not
really dependent upon your using Dupla products. It's more a methodology
than a mantra. Even George Booth (gosh George, you've been getting hit
regularly over this haven't you?) bought a lot of his Dupla equipment on
sale, when That Fish Place dropped the line a few years ago. You don't have
to use their equipment, or even their fertilizer products, in order to set
up and maintain an "Optimum Aquarium". It can be a matter of convenience, as
Karen noted. But Dupla does make quality products - if you are able and
willing to pay the prices asked. I have only bits and pieces but I'm glad I
coughed up the money for them - I like quality.

The exact same thing I'm sure applies to Aqua Design Amano products and his
style of tanks. I'm on the Nature Aquarium Imports discussion list and they
recently posted a notice about a sale on their substrate products. When I
contacted the company about shipping costs to Canada, I almost had a heart
attack - it would cost more in shipping than the actual Aqua Soil cost. Even
Amano himself admits that his tanks are more about philosophy and art than
about his line of products.

James Purchase


by Alysoun and Andrew <alysoun/>
Date: Wed, 27 Jan 1999

Roxanne Bittman lamented:
> It's not possible to push crumbled laterite (Substrate
> Gold, etc.) into a water-filled, established aquarium.
> Guess I didn't make this clear.
> Roxanne Bittman

Yes, it is!  I've used Substrate Gold in this way. As I recall, you add
a little bit of water, smush it into balls, bake it at 350 or so for a
few minutes, and shove it into the substrate.  It's been a while, so
someone else should probably post a better set of directions.  Maybe
Jennifer Glover would be willing to post her Substrate Gold Christmas
cookie recipe?  

Alysoun McLaughlin


by krandall/
Date: Mon, 08 Feb 1999

>However, for our practical purposes (i.e., growing aquatic plants), is there
>really an *observed*, rather than *hypothetical*, advantage to using bona
>fide laterite rather than Substrate Gold?

It is my understanding that Substrate Gold _is_ laterite.  If you're
talking about red "art clay", that's something else again.  Remember, that
even all laterite isn't made equal.  For those interested in one person's
experiences with a number of different laterite products, here's a list of
the products I've used, and how they have compared  some of these products
are not currently available, but I've included them in case someone finds
some in a dusty corner of a store somewhere.

Dupla laterite:  

Excellent plant growth
Easy to use
Stays put well
Settles out quickly even when plants are uprooted
Now (at least temporarily) not available in North America

Aquarium Products laterite:

Good plant growth
Easy to install initially if left in balls - messy if crushed
A little more likely to cloud water when plants were uprooted
Much less expensive than Dupla
No longer produced

Thiel laterite:

Good plant growth
Funny texture, less clay-y and less red than other laterites
No problems that I remember with either installation or uprooting plants
Sounds like Albert has dropped the product

Substrate Gold

Excellent plant growth (comparable to Dupla)
>From what I've read here, the directions say to use more than recommended
by Dupla.  I didn't bother to read the directions, and used Dupla-like
quantities with excellent results
_Slightly_ more likely than Dupla to cloud water if you're not careful
filling the tank, but no worse than any of the others.  
No problem uprooting plants
Much less expensive than Dupla
Shipped damp, so shipping costs (based on weight) are probably higher, but
less dusty to work with
Can be purchased in big plastic containers, making it easy to store

Tetra Initial D

I have not been happy with growth
_REALLY_ hard to get out of the water if you let it escape from the
substrate during set-up.  Not only clouds the water, but turns it green
(not algae, the stuff itself is green)
Easy to obtain

Maybe others can fill in their opinions of the other commercial substrate
products, particularly if they've had experience with more than one.  It
sounds like the people who are using Flourite are happy with it so far,
though it's been around for a short enough time that it doesn't have much
of a track record yet.  I have personally seen beautiful tanks set up with
the Sera product (is it Flora-depot?) and I know Olga and James have
expressed satisfaction with Terralit.  Have either of you had experience
with Dupla laterite so you can give us a comparison?  Has anyone tried the
Red Sea laterite yet?

RE: Ducks, Laterite and Clay... Amen!

by "James Purchase" <jpurch/>
Date: Mon, 8 Feb 1999

This is another one of those I said, he said posts.... (and I promise this
is the last I'm going to say on the subject of laterite for at least a

I said...
>Alysoun McLaughlin is getting bored with our discussion of Laterite...
>Oh God! Here I go again.... Quack, Quack, Quack....
><further explanation of the specific qualities of laterite vs. other clays,

Alysoun said...
>I do understand the distinction, James!  <g>

>However, for our practical purposes (i.e., growing aquatic plants), is
>really an *observed*, rather than *hypothetical*, advantage to using bona
>fide laterite rather than Substrate Gold?

Whoa! Alysoun, please refer back to my initial post. Read it again, please.

I was discussing the common confusion, at least among those who don't know
much Geology, between a clay which is called a laterite and all other clays.
Heck, even Roger Miller used laterite and kitty litter in the same sentence
a few days ago <g>.

If you will recall, I said that "clay" is a relatively generic term,
referring more to a mineral material with a particle size of less than 0.002
mm. The word "clay" doesn't tell you _anything_ more than that. It states
_nothing_ about the actual minerals involved, nor their origin or age.

I believe I mentioned Bentonites (Fuller's Earth), a common enough type of
clay which is used in a lot of "kitty litters", due to one of it's physical
properties - it absorbs moisture, expanding in the process. Great thing to
soak up your cat's pee, but I'm still not convinced about it's suitability
as an aquarium substrate. At least, not in any of _my aquariums_ (I don't
have a cat who wishes to pee in my aquariums. hehehehe).

I also know that many people have experience with pottery clays, most
usually Red Art Clay. I have a bag of it, I have used it in the past, I will
use it in the future. I can tell you that I have OBSERVED, in my own tanks,
a very definate difference between a substrate using Red Art Clay and one
using Duplarit G. Regardless of the "hypothetical" differences - there are
definately "observable" differences.

You seem to be mis-reading me on at least one level. When I said that while
all laterites are clays, but not all clays are laterite, I meant just that.
I drew absolutely NO distinction between Dupla brand Duplarit G and Karl
Schoeler's Substrate Gold.

I have admitted on numerous occassions that my only knowledge of Substrate
Gold is secondary - I've never seen it nor used it. But, that aside, from
everything I have been able to read on it, Substrate Gold IS "genuine
laterite", and I would venture an extremely well educated guess that it will
give results every bit as good as Dupla's more expensive product.

As Roger Miller pointed out a few days ago, not all laterites are the same,
and some may be better at growing aquatic plants than others, but from what
I can tell, the major difference is that some types of laterite might be
more prone to leaching into the water column and causing a reddish stain or
cloud when disturbed. But this has nothing to do with their effectiveness in
growing plants. It is merely a housekeeping issue and can be rectified by
placing the laterite layer under a good layer of clean gravel and make sure
that your tanks have good mechanical filtration.

Your original post indicated to me that you were confusing other clays with
laterites. That's where the duck analogy comes in. Many people who post
here, and many, many more who post to the USENET rec.aquatic.plants
newsgroup (the great unwashed?) frequently make comments like "I've got a
Dupla style tank with kitty litter substrate..." (substitute any number of
alternatives for the words "kitty litter"). There continues to be a great
number of people who are thinking this way. While I have said that, in my
view, the use of actual Dupla brand products is not necessary to have a
genuine "Dupla style" tank, I think that at the very minimum the substrate
of such a tank should contain laterite, not kitty litter, not red art clay,
not play dough.

I do not say that Red Art Clay cannot be used in a substrate with much
success, especially when mixed with a small amount of fertilizer, preformed
into balls and inserted into a plain gravel substrate. I do this myself, and
it does work well for heavy feeders. But it 'ain't laterite.

Now, as to your latter question :

>"Perhaps I should have phrased it differently... if it's not a duck, but
>you really care about is the wings and feathers, will a pheasant do?

VERY good question. One that has bugged me for years. One that I hope to at
least make some stab at answering with my planned "system study". I am a
firm believer that there are many ways to skin a cat (you know, I hope the
SPCA doesn't get wind of how we abuse cats on this list), and many roads
lead to Rome, and I think that there are many ways to grow aquarium plants.

The Dupla strategy is successeful - it has been proven time and again by
aquarists from all over the world (that's a direct quote from George Booth).

Steve Pushak's HTBASS strategy is successeful, at least in the hands of a
careful and experienced person - I have spoken numerous times here on the
fact that I have a tank set up following Steve's methodology and it works.

So, lots of things work - if you know what you are doing. But, and this is a
VERY big "BUT", not everyone knows what they are doing. This is not a
put-down to anybody, it is just a statement that appears to me to be true.
This hobby contains a lot of people with a wide range of abilities and
backgrounds. Just as some cooks can make dinner without referring to a
recipe, while others might need one in order to boil an egg, some people
make substitutions which work, others make substitutions which don't. Those
who are successeful generally matched the properties, both chemical and
physical of their substitution with the original material. Those who end up
failing generally follow some half assed advice they got from their sister's
boyfriend's brother's schoolteacher, who got it off of the Net.

So, if you _want_ to use kitty litter in your substrate, be my guest. If
your prefer Red Art Clay, go ahead. But never assume that such substitutions
are going to work as well as something which has over 20 years of documented
research behind it. It may, or it may not.  And if you _do_ choose a novel
substrate, do all of us a favour and document your set up, maintenance, and
results carefully and post it for others to learn from. That's why we are
all here (I think).


James Purchase

RE: Laterite

by "James Purchase" <jpurch/>
Date: Fri, 5 Feb 1999

Richard Sexton is wondering about laterite -

>Ok, so whats the deal with this stuff? Is red potters clay good enough ?
>is kitty litter as good ? Does the brand of laterite make any difference ?

>The Dupla stuff was supposed to be from Malaysia as far as I know, will
>laterite from other countrues work ?

For a discussion of exactly _what_ laterite is, try this URL - It is an article by Kaspar Horst (Dupla
co-founder), which appeared in the German language magazine Aquarium Heute.
There is also a lot of information in the archives of the APD on laterite
(thank's to the Geologist's on the list).

Red potters clay (Red Art Clay is the brand I'm most familiar with) is not
laterite. It has _some_ properties which are desirable for our purposes
(high iron content, high CEC) but others which we don't (it can form an
almost colloidial solution due to how finely it is ground).

Kitty litter is not laterite (not even _close_). Most kitty litter (the
kinds made of clay minerals anyway) is made from Bentonite (Fuller's Earth),
a type of clay which absorbs moisture and expands when wet, forming a rather
gelatinuous, gooey mess. Why someone would want it in their aquarium
substrate is beyond me (Dan Quackenbush be darned).

Laterite is:
 1.)a type of clay
 2.)high iron content
 3.)has suffered heavy leaching
 5.)under tropical conditions
 6.)over geological time.

There are many types of clay - the term clay only really refers to the
particle size of the material. A number of clays are available which have
high iron content - the red colour in some "pottery clay" is generally due
to the presence of iron oxides. The unique properties of laterite which made
Dupla (and several other companies) sit up and take notice are due to the
last three points - highly leached, formed under tropical conditions over
geological time. Dupla obtains their laterite from locations which have
tropical conditions now, in the  latter years of the 20th century. But the
laterite formed hundreds of thousands, if not millions of years ago. Back
then, (I was only young, so my memory may be spotty) the geography of the
planet was quite different from what it is today - coral fossils have been
found in the Canadian Arctic, indicating that at one time the land area
there enjoyed tropical conditions. Most of North America, at one time or
another, was tropical. I grew up in eastern Canada, on the island of Cape
Breton, and the eastern end of the island has extensive coal supplies -
these formed millions of years ago from tropical swamps. The place is far
from tropical in the modern era.

So, it is quite feasible that true laterite exists in North America. Karl
Schoeler's company sources Substrate Gold, a true laterite, from North
America, and from what I hear it is just as capable of working in an
aquarium as Duplarit G. The enterprising aquarist could consult local
Geology Departments to determine if any deposits of the stuff are in their
area, or they could just contact Karl and buy his product (it is cheaper
than Dupla's stuff). There are also other commercial sources - I understand
that Red Sea has just introduced a Laterite substrate additive.

So Dupla's departure from the "New World" need not send us all into a tizzy.
We, and our aquariums, will survive. I just won't have as many high tech
toys to play with.

>FWIW, the first real luck I had with plants was when I was in '73
>or so when I dug up some red clay from my back yard and put some
>in the bottom of a small dish, covered it with gravel and stuck
>3 Aponogeton crispus (or what passes for crispus) in it. They
>filled a 30 gallon tank.

That doesn't surprise me a bit Richard. By any chance were you living in
Toronto at the time? The Don Valley Brickworks, just down from where I live,
has deposits of clay which according to my research have lain there
undisturbed for the last three hundred thousand years. I've got a number of
pots of aquatic plants growing in the stuff and they are doing great.

James Purchase

?Laterite injectible?

by "ALEX PASTOR" <alexp/>
Date: Sat, 6 Feb 1999

Someone was wondering about what to do if they don't have any balls
(laterite balls that is).

I was just thinking: what if you make a slurry of laterite (or Substrate
Gold)?  Draw it up into an irrigation syringe and push the syringe down into
the substrate and inject.

Irrigation syringes are all plastic with a curved tip.  The tip can be cut
so that the hole is the right size to pass the slurry.  You can get one from
your dentist (for free, if you're nice) or buy one from the pharmacist at
your local drug store. Oral surgeons often give them out to their patients
after wisdom tooth extraction. (Ouch).

All those people who want to augment their substrate should be able to do so
without major work on their tanks.

G. Kadar

Just for the record

by IDMiamiBob/
Date: Tue, 9 Feb 1999

Karen Randall writes:

>If you're talking about red "art clay", that's something else again.

Just for the record, it's redart, and while it is used in pottery making, it
isn't an "Art clay".  Folks who may go looking for red art clay without
recognizing the distinction will probably end up with colored modeling clay.
I see a lot of fols on the list calling it "red art clay", and it can lead to
confusion for some, just like "Flourite" did for the geologists on this list
last summer.  There is a mineral called flourite, but Flourite is an aquarium
Bob Dixon

laterite.....Substrate Gold

by Karl Schoeler <krsfert/>
Date: Sat, 06 Feb 1999

James Purchase wrote:  (edited somewhat)

> The Substrate Gold you have in your
> aquarium should work just as well as "genuine" Dupla laterite. It is
> probably not the exact same mineral (as Roger Miller pointed out) but it
> will be close enough for our purposes. As far as the importation of "nasty
> tropical bugs", the US Dept. of Agriculture is very strict about that sort
> of thing - soil is _not_ allowed to cross the U.S. border.  Dupla was required to
> prove to the Department of Agriculture's satisfaction that Duplarit G was
> free from any nematodes or other soil borne pests before it was allowed into
> the country. I believe that at least one shipment was held at the border for
> that reason.
> Mr. Schoeler doesn't have that same constraint, so his product can be
> cheaper (read as less expensive).

James,I'm not really replying directly to you so much as to several questions
that have been posted on the APD lately.  However, your post does
provide the proper forum, so thank you!

Some of this information is available on my website, some is not.8-)
Substrate Gold has been certified by the University of Minnesota Plant Disease
Clinic to be free of nematodes.  I was not required by any agency to have this
test performed, but I thought it made sense.  The test is the same, whether for
the USDA, or idle curiosity.  The cost is the same also.8-)  Since it has been some
time, my best recollection is that the test was about $25.00.  I thought it was
very cheap, and a good investment.



> Roxanne wrote:
> >>Once youhave an established tank, the balls are very handy to
> push into the substrate every 3-6 months.  <<
> Can't you make your own balls with laterite by wetting and baking it?
> Ask George about _his_ balls (hopefully, good taste will prevent a
> predictable response like "Pushing them into the substrate is too painful"


Substrate Gold, which is improved laterite, also is available in this form.
We prefer to call them Nuggets,  thus reducing predictable responses.8-)
We don't advertise them but they sell anyway.  It is much cheaper to make
your own and the instructions on each package of Substrate Gold also
outlines how to make Substrate Gold Laterite Nuggets.



Re:Dosing levels for Substrate Gold

by Karl Schoeler <krsfert/>
Date: Sat, 13 Feb 1999

Michael Nielson wrote:

> I have read in the past posts from persons who thought that a little Dupla
> laterite is good, then alot must be better.  They reported problems with
> excessive algae (I think).

Michael,I believe that using Dupla laterite in the same manner as Substrate Gold
laterite would yield very good results.  I also believe that using Substrate Gold
laterite in the same manner as Dupla laterite would yield results of a similar
nature.  IMHO, excessive algae cannot be attributed to the use or "abuse" of either
product.  I would attribute the problem to one or more of the factors relating to
water column imbalance such as lack of plants,
excessive duration of lighting, over-feeding, and so forth, especially during the
first year.

> Karen Randall reported using Substrate Gold at the Dupla dosage and
> achieving good results.  Others have used the recommended amounts with
> good growth as well.

Yes, I am well aware of Karens' success.  Noting her prowess in the world of aquatic
plants would we dare expect anything different? 8-)

> My question is how did you arrive at your dosing levels for Substrate
> Gold?  Any ideas why it does not seem to cause problems at higher levels
> than the Dupla stuff?

Initially, Substrate Gold was tested by the members of the Minnesota Aquarium
Society.  Selected members were given samples and general instructions.  The results
of those tests lay in the increase in HAP entries during the following year.  During
that same time, I had set up several tanks using a variety of methods and dosages in
the substrate.  Through trial and error I arrived at what I now suggest on the
label.  Not that it is cast in concrete, but it has been tested and proven for best
plant growth and longevity in the substrate. 8-)



Feldspar -> clay (kaolin, bentonite, etc.) -> laterite

by Wright Huntley <huntley1/>
Date: Thu, 25 Feb 1999

The geological processes that create laterite may follow several
different paths. IDK.

One I'm a bit familiar with is the sequences partially on the way to
laterite. Feldspar, making up more than 50% of the earth's crust is an
alumino silicate also containing calcium, sodium or potassium.
Geothermal action can remove the other materials to leave an aluminum
silicate, which develops clay-like properties depending on the water of
hydration in the final crystalline (or platelet) forms. White kaolin
china clay is a particularly pure form. [Bentonite usually goes via
volcanic action and the conversion of glassy lavas.] 

Nature, being messy, often leaves other "stuff" behind, too, like iron
oxides or sulfides, etc. Many red clays used for pottery and adobe fit
that area. they vary in their "fluxing" ability (how high firing is
required to fuse the particles together) and the final color of the
fired ceramic. The fluxes are often lower-melting point compounds that
can get the aluminum silicate partially into solution at high
temperatures, without allowing complete meltdown. The cooled product
then is nearly totally insoluble and withstands years of use in the
kitchen. "High Fire" ceramics also render lead oxide, etc. insoluble,
too, so they are safer for eating utensils.

Clay particles are easily washed out of the hills where they were formed
around geothermal springs. They become (contaminated) sediments in the
bottom of canyons and river valleys. Rain then can begin the long
ultra-slow leeching process, whereby anything soluble is carried out to
sea. In rain-forest (tropical rainy) regions, the soil quickly becomes
infertile and nearly inert as all the solubles are grabbed by flowing
rain water. Slowly, the silicates can even be reduce to oxides as SiO2
is gradually dissolved out of them. That's the process that possibly
takes thousands of years. Silicon dioxide (pure amorphous quartz glass)
isn't very soluble, even in highly corrosive pure distilled water.

[This last paragraph is mostly conjecture on my part, while the earlier
ones actually have some basis in my experience.]

Firing any ordinary clay to form a true ceramic (even if crushed later)
probably ruins it for what we want. The porosity probably goes down like
mad. [Partial firing, at lower safe levels, is what I suspect is done
with "Profile" and similar products.]

I have had excellent results using red potter's clay, baked at a way low
temp. compared to normal firing.

By rolling long cylinders and cutting them into 1/2" long x 1/2"
diameter plugs, I could bake them to a semi-insoluble state in the oven
at about 350F. I imagined a 2" square grid on the floor of a 55G tank.
Placing one plug at each intersection, I covered the bottom. Gravel to
just cover, was added, then a thin layer of peat. A final thick gravel
layer built the substrate up to about 3". I sloped it a little from
front to back, so the front was about 2" deep.

That tank has been moved twice, and the plants still go crazy in it
after 3 or 4 years. When I root through the substrate, the plugs are a
ball of slimey clay, but uprooting plants, etc., has never given me a
cloudy tank. I added too much peat, so I got some noxious gas burps
during the first year or so. [*Never* add more than 5% of your substrate
as organics. :-)]

I use less light (80W) than many of you, and have slowed plant growth by
dropping CO2 injection during the past couple of years. Nevertheless, it
is a way to go that's pretty easy and gave me good results.


- -- 
Wright Huntley, Fremont CA, USA, 510 494-8679  huntley1 at home dot com

One big difference between a Libertarian and a Demopublican is the 
Libertarian knows it's not a waste to vote against a Republocrat. 

Baking potter's clay -- time

by Wright Huntley <huntley1/>
Date: Fri, 26 Feb 1999

Hi all,

I haven't done it for some years, so I think it was about 30 min at
350F. Basically, to get it dry and hard enough that it didn't powder and
cloud the water.

Since "Profile" is less than US$0.50/lb. at Home Depot, I wouldn't dream
of doing it again. :-)


- -- 
Wright Huntley, Fremont CA, USA, 510 494-8679  huntley1 at home dot com

One big difference between a Libertarian and a Demopublican is the 
Libertarian knows it's not a waste to vote against a Republocrat. 

What's the truth about laterite

by "Roger S. Miller" <rgrmill/>
Date: Mon, 3 May 1999

On Monday, Samuel Johansen wrote:


> It goes on to say that true laterite is found in Hawaii, West Indies,
> Australia, Queensland, India, and China. Not the USA or Canada.

Laterite is a type of soil that forms in tropical climates.  Canada and
the upper 49 states of the US are not currently in tropical cimates and as
a result there are no *recent* soils in the 49 upper states or Canada that
can truly be called laterites.

(No Title)


However...  all of North America has been in tropical climates at times in
the geologic past and there are areas in North America where small inliers
of ancient soils are preserved as rocks.  Some of those ancient soils
happen to be laterites.  The most well-known of those are probably the
bauxite deposits in Arkansas, but there are other areas as well.  In all
cases I think the ancient laterites are rocks and not something a soil
scientist is going to get worked up about.  They're definitely in the
geologists' domain.

> It seems obvious to me that what people are reffering to as laterite in
> the USA is not laterite at all, but clay.

That is quite possibly true, but there are ancient deposits formed from
lateritic soils so you can't say just on that basis of a product's
originating in North America that the product definitely isn't laterite.
It would be possible to tell with an X-ray diffraction analysis of the
material (which should be fairly inexpensive), probably coupled with a
chemical analysis.

> So what is Substrate Gold, clay or laterite? Where does it come from?

Karl Schoeler (spelling?) would have to answer that.

> Why aren't people concerned about this?

(No Title)


Roger Miller
who is not a user of Substrate Gold or any other make of iron-bearing


by "Roger S. Miller" <rgrmill/>
Date: Thu, 8 Apr 1999

Christopher Coleman replied to an original post from Robert H, to which
Mr. H now responds...

> Well Chris, I think you need to relax your tone a bit here. I am not
> trying to make headline breaking news here, but to only have a better
> understanding of it myself.

You have a reasonable goal, and Chris's response was a bit terse, but
lot's of us get that way about the upteenth time we deal with the same

> >> have always thought the term was over used to describe
> >> just about any type of clay.
> > It is not clay.  This is a misnomer.  Laterite is a soil containing
> > a mixture of minerals.  Understanding laterite is possible by
> > understanding what clay is and than realising laterite lacks any of 
> > properties.
> There have been numerous refrences to laterite as clay on this list,
> rec.aquaria and many other forums. Laterite does NOT contain a mixture
> of minerals to any extent. Most has been leeched out and laterite is
> formed by weathered basalt.

Are you surprised that many internet forums might be providing you with a
hat full of misinformation?

If you read the archive (I know, its difficult to sort out all the
references to "laterite") you wil find that laterite is a clay only in the
sense that it's "really fine grained stuff" and then only if it has been
ground up really fine.  You will also find that laterite is composed
largely of oxyhydroxides of iron and aluminum - most commonly aluminum.  
It contains a small proportion of other minerals, including the clay
mineral halloysite.  Many rocks and most soils have a higher clay mineral
content than laterite.

The constituents of laterite are minerals.  Laterite is leached of any
mineral that is at all soluble, but the material that's left is still
mineral.  The common minerals have obscure (to the layman) names like
goethite, gibbsite, boehmite and diaspore.

Furthermore, laterite does not form just from basalts.  I don't think that
laterization depends much at all on the parent material. Even the very
restrictive group of economically important laterites (bauxites) form on a
wide range of parent materials.


> >>  "If you would like a response from a whole group of clay minerals
> >> scientists
> > Again.  It is not clay.

> Well then maybe you should pose a question to this server of "clay
> mineral scientists", who according to you arent clay mineral scientists.

I don't think Chris was implying that the people on the list aren't clay
mineral scientists.  The point is that laterite contains few clay
minerals, so the clay mineral scientists are the wrong crowd to be talking

> > So can I infer from all your rambling that you think laterite is found 
> > in the USA? Can you tell me where?

By my reference (Lefond, ed. 1975.  "Industrial Minerals and Rocks"),
lateritic (aka bauxitic) material is found in several areas of the US, all
of them "fossil" deposits:  12-23 million year old deposits occur in
Oregon and Washington, 35-55 million year old deposits are found in
Arkansas, Alabama, Georgia and Mississippi and 270-320 million year old
deposits are found in Missouri and Pennsylvania.

If you live in one of those areas and are interested in finding out more
about them you might be able to contact local offices of the US Geological
Survey (Department of Interior), state Geological Surveys or Bureaus of
Mines, or local schools and/or universities with departments of Geology or
soil science.  In all of the U.S. occurences the laterite is likely to be
a rock and not at all clay like.

In addition there are other types of iron deposits that occur all over the
world.  Finely crushed ore from some of these deposits might make a
suitable substitute for laterite.  But as always, YMMV.

Roger Miller


by Steve Pushak <teban/>
Date: Mon, 12 Apr 1999

Robert H wrote:
> Steve wrote:
> > The term laterite or
> > later-soil is so vague and imprecise in geophysical terms that its
> > largely a moot point.
> So would I infer from this then that the aquaria definition of laterite
> is then just a broad term applying to most any soil substrate?

The aquaria definition is borrowed from the scientific definition. It
does not refer to just any soil substrate, it refers to those types of
soil substrate additives which can be legitimately qualified as laterite
in the scientific sense.

The problem with the term laterite is that it does not refer to a single
homogenous material with a single chemical composition; it is a very
large class. The terms for various types of clay minerals on the other
hand, refer to specific chemical, mineral compounds. Anyone who had done
a significant amount of research on The Web about soil science will be
aware of this. Laterite refers to many vastly different mineral
compounds. It can refer to soils which merely contain a large proportion
of iron and aluminum hydroxides. It need not be a "pure" mineral to
qualify as a lateritic soil. In fact, if you were going to choose a soil
for your garden, laterite would be a poor choice because it lacks many
important minerals necessary for plant growth.

To head off a misconception, the clay textured mineral component which
is common in soils, is almost always a mixture of several of the "pure"
clay minerals and contains all sorts of "impurities". It will also be
mixed with silt, sand, gravel, rocks, leaves, insects, worms, bacteria,
humus, and other organic material which is in some stage of

As a medium for hydroponic growth in the aquarium, laterite has two

i) laterite is relatively inert and non reactive. The lack of minerals
is not a problem because it is used in a hydroponic methodology where
almost all the nutrients are in solution. The property of being inert is
not intrinsically good or bad. It may be desirable to minimize other
effects such as oxygen demand or the release of humic acids or the
release of carbonate pH buffers but it depends upon the overall

ii) laterite has available iron (I believe) which stimulates growth by
providing iron in the substrate. High levels of iron in solution, while
they might stimulate growth, would also stimulate the growth of algae.
Iron in the substrate also plays a roll in stabilizing phosphates and
may play a role in providing these to the roots of aquatic plants. Other
soils can also perform this role (I believe)

> The
> physical properties then can vary from one manufacturer to another?

No, the physical properties of any laterite based substrate additive
will probably be relatively consistent, although there is possibility
for variation. No manufacturer is going to use bauxite as laterite for
example. Suitable aquarium laterites would share the following
characteristics I think:

a) pH would be between 6 and 7 although it will probably not contain
significant buffering capacity. Almost certainly there will be no
carbonates, or sulphates and virtually no organic compounds.

b) the texture will be somewhat fine. Some particles may be sandy in
texture but there will probably be some that are clay like in texture as
this is important for the availability of iron.

c) the chemical composition will probably contain high amounts of iron
hydroxide but may also contain iron hydroxide. There could also be
"impurities" such as silicates and trace minerals. These could improve
the nutrient suitability of the additive without altering its primary
characteristic of being relatively inert and having minimal affect on

There are a broad range of other possible (non laterite) substrate
products which could be manufactured. These may or may not have pH
buffers (i.e. humic acids as from peat), might have organic material
(peat or humus for example), might have sequestered minerals of many
kinds. The texture could be primarily coarse such as sand or extremely
find like sand. The method of application and the other methods of
fertilization would be tailored according to the substrate materials.
The emphasis could be primarily hydroponic or geoponic.

> The research I have done thus far from scientific sources on the net
> have a much clearer definition. 

The definition of laterite may be expressed in clear terms but is vague
in the sense that it includes a great many significantly different
materials. Geologists do not like the term laterite because it is not a
precise classification. It does not refer to a single mineral compound.
I also believe that among geologists, there is not agreement about how
the term laterite should be used: in the narrowest sense or in the
broadest sense. The term is not used consistently in the literature.

> If it is so commonplace that laterite
> exhists in North america, then it only makes sense that it would be
> documented by someone and known by someone, anyone in the scientific
> community.

I don't know what Robert's point is with this statement. He seems to be
saying A implies B; B is false therefore A is false. Both of the
assertions (A->B and not B) seem doubtful.

And I still don't know what the point of Robert's original posting was.
I think he is now saying that he is questing for information about
laterite. The North American angle seems to be a false trail. ;-)

Steve Pushak                              Vancouver, BC, CANADA 

Visit "Steve's Aquatic Page"
 for LOTS of pics, tips and links for aquatic gardening!!!

Oregonn laterite

by "Roger S. Miller" <rgrmill/>
Date: Wed, 15 Mar 2000

On Wed, 15 Mar 2000, Robert H. wrote:

> Thats interesting James..(and I am not going to get sucked into this
> argument again!) but it seems to be talking about lateric rock formations,
> not lateric soil...

(No Title)


That's awfully old dirt, but pretty young as rocks go.  Age might not have
that much to do with it though because laterites (even those in modern
soils) are often rock-hard.  I think that's why some laterite products
are granular, rather than powdery.  They're probably rather rock-like to
start with, then they're just crushed and sized for sale.

The abstract also describes the laterite as "high-silica laterite" which
implies to me that they probably have a higher clay mineral content than
is common for laterites.  That description makes them sound very similar
to some of the red soils in the SE US, which I've seen described in
technical literature as "lateroid"  soils.

Those paleosol laterites might work for aquarium use, but before y'all in
the Portland area go digging up your hillsides you should probably see if
the report includes a chemical analysis of the laterites.  Most laterites
are predominantly aluminum hydroxides with enough iron to make them red,
but perhaps not enough iron to be particularly good in your tank.

Roger Miller

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