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More Info on Substrate

Contents:

  1. [plant][long] BUILD A BETTER SUBSTRATE
    by jkelly-at-landau.ucdavis.edu (Jim Kelly) (30 Sep 1994)
  2. [plant][long] BUILD A BETTER SUBSTRATE
    by jkelly-at-landau.ucdavis.edu (Jim Kelly) (30 Sep 1994)
  3. [plant][long] BUILD A BETTER SUBSTRATE
    by jkelly-at-landau.ucdavis.edu (Jim Kelly) (2 Oct 1994)
  4. [PLANT] Interesting results and advice
    by jkelly-at-landau.ucdavis.edu (Jim Kelly) (24 Jan 1995)
  5. [PLANT] Interesting results and advice
    by jkelly-at-landau.ucdavis.edu (Jim Kelly) (27 Jan 1995)
  6. Vermiculite info
    by nfrank-at-nando.net (Neil Frank) (Mon, 28 Aug 95)
  7. Webb-Kelly 29 gallon setup
    by ac554-at-freenet.carleton.ca (David Whittaker) (Fri, 4 Aug 1995)
  8. Why doesn't anything live in substrate
    by George Booth <booth/lvld.agilent.com> (Mon, 10 Jul 2000)

[plant][long] BUILD A BETTER SUBSTRATE

by jkelly-at-landau.ucdavis.edu (Jim Kelly)
Date: 30 Sep 1994
Newsgroup: sci.aquaria

George Booth (booth-at-lvld.hp.com) wrote:

: Was there any indication of how much CEC is necessary?  Clearly, humus
: has more but does laterite have enough?  

No, there wasn't.  The general indication in many books was that latisols
(lateritic soils) made poor farming material.  This could be for many
reasons such as the fact that laterite forms a concrete-like brick which
is used for construction and roadways in some areas.  A low CEC allows
nutrients ions to be washed away by rain (or aquarium water), but you are
are replenishing them with additives (aren't we all!), so it's probably
not such a big deal for us.  The reason I kept mentioning laterite's
low CEC is that many netters said that this was its primary function.  If so
then we can clearly do better, but we could do worse also:  I imagine
sand and other gravels commonly used have a CEC which is for all practical
purposes zero.  Besides, the grain size is much too large to have an effect
(roots must be in intimate contact so any clay will work better).  Aquarium
laterite has a fine particle size and so should be much better.

I should mention that I looked into this stuff during the past summer with
hopes to prove to myself (well, maybe you too ;)) that laterite wasn't
worth even a moderate price tag, or if it was I wanted to know more about
why.  It still seems to me that laterite might be extremely valuable
for its phosphate holding properties.  I recall that you posted a while
back that the combination of laterite and heating cables in the SST seemed
to prevent algae from thriving, so maybe we could show that the laterite
does play a key role through some half baked experimentation?!  This
phosphate fixing property is, incidentally, another reason that latisols
make poor terrestrial farming soils:  many plants become phosphate deficient
without heavy fertilization.

Jim.

: > * HUMUS is the end product of the decomposition of organic matter.
: > * Layer silicate clays form small colloids in the soil with a
: > * etc

: Is there a description of the physical properties of these materials?
: How suitable are they for an aquarium substrate?  Would they get into 
: the water column and stay in suspension for long periods (like the 
: infamous Aquarium Products "Laterite")?

: -----------------------------------------------------------------------------
: George Booth                         "The power of accurate observation is 
: booth-at-hplvec.lvld.hp.com              commonly called cynicism by those who 
: Freshwater Plant Tank Technology      have not got it" - George Bernard Shaw.
: -----------------------------------------------------------------------------

[plant][long] BUILD A BETTER SUBSTRATE

by jkelly-at-landau.ucdavis.edu (Jim Kelly)
Date: 30 Sep 1994
Newsgroup: sci.aquaria

George Booth (booth-at-lvld.hp.com) wrote:

: Is there a description of the physical properties of these materials?
: How suitable are they for an aquarium substrate?  Would they get into 
: the water column and stay in suspension for long periods (like the 
: infamous Aquarium Products "Laterite")?

Sorry, I forgot to edit out your signature and answer the 2nd question (I'm
new to this "vi" editor).

Humus is completely decayed leafmold.  I have seen it mentioned as a potting
component in gardening books, so I imagine it is available somewhere.  I
looked locally (and got a few odd glances) but all I could find was
"leafmold" (and of couurse peat) and I don't know if this stuff is completely
decayed.  I wished to avoid things like peat that would further decompose
in the substrate.  BTW, I just set up a new 55g using only the puffy
vermiculite and #3 sandblasting sand in the substrate.  The vermiculite
was wetted as much as possible by adding to water in a bucket and squeezing
to remove the air.  Some sank in the bucket but most still floated, which I
hope time will cure.  I had some in a pot with sand over the top in the 55
this summer and when the plants were uprooted no vermiculite floated to the
top.  Anyway the bottom of the 55 is pure verm*, then verm*/sand and finally
covered with about 1" of sand (about 4" in all).  There was no cloudiness
after adding the water.  There is also an UGF with the tubes extending above
the water on both sides.  A cheap low pressure/ high flow pump pushes water
through drip irrigation on/off continually adjustable valves (not the gal/hr
type -- those are made for high pressure).  The flow is set so that if the 
nozzle points downward into the tube, the water stream breaks into drops
about 1/2" from the exit point.  This is an easy way for me to adjust the
flow to a constant value if it fluctuates over several days.  This is, of
course, to keep the substrate aerated.  It was not my idea, but I'm sure
you'd remember who thought of it -- works like a charm!  Anyway, I've found
that more than anything the anubias really hate anaerobic bottoms.  I have
a 10g where their roots wouldn't even penetrate the gravel, so I wanted to
be sure I corrected it this time around.  The tank has only been going
one week -- too early to judge but the water is crystal clear and the plants
are growing so we'll see.  Just for reference there are 4 40w bulbs above
and DIY yeast CO2 bubbling into the intake of an aquaclear power filter (the
bubbles collect in the sponge and the CO2 is very high on my poor quality
Tetra CO2 test kit.

Jim.


[plant][long] BUILD A BETTER SUBSTRATE

by jkelly-at-landau.ucdavis.edu (Jim Kelly)
Date: 2 Oct 1994
Newsgroup: sci.aquaria

Craig Bingman (cb77-at-konichiwa.cc.columbia.edu) wrote:

: I do have a question, though.  It seems that one of your assumptions is
: that more cation exchange capacity is necessarily better.  Seems to me 
: that there is some danger that the a substrate with immense cation
: exchange capacity might just become a bottomless pit for certain cations.
: If there are a range of affinities in various sites in the substrate,
: by definition, you are likely to fill the highest affinity sites first
: (unless there is a kinetic effect, and the highest affinity sites are
: very slow to take up metals...)  So.  Cations bound at the highest 
: affinity sites are going to be most inaccessible to the plants.

Good point.  There can be too much of a good thing!  As I mentioned,
different cations are attracted to different materials with different
affinities, and there might be some danger of the bottomless pit effect
if you use only one clay (as I have done with my recently set up 55).
I think it's safe to assume that in the wild plants generally grow in
higher CEC environments than are present in most people's tanks.  I'm
talking about plants with large root systems and root hairs of course.
They generally grow in muck, fine clay, sediment, etc. that would seem
to have a very high CEC.  Maybe the variety of stuff they grow in has
a high affinty for many different cations and no one nutrient gets
singled out and becomes deficient, or maybe things just aren't ideal
and the plants adapt in other ways.  I'm not sure this answers your
question, but just in case let me emphasize these points which I'm
fairly sure are true.  First, high CEC has nothing to do with affinity
for cations, but only measures the total number of charged sites per
mass of substrate irregardless of the affinities for cations.  Second,
each charged site which contributes to the CEC is always filled, and
there is no such thing as one site filling first and another filling
later.  However there may be a preference for certain cations to be 
found at certain sites.  If those sites predominate, other cations will
be forced into solution in favor of the preferred cations, and the
cations in solution will spend less time in the vicinity of the roots
(and will be washed away with water changes).  If the affinity was very
strong for the preferred ion, there might be a deficiency of this 
nutrient in the plants (I believe this was what you're referring to?).
Third, the CEC is *defined* as the charge/kg corresponding to sites
from which most ions are readily exchangeable.  Brady says they 
measure it by leaching the soil with something like ammonium (and no
other cations) in solution.  This is done for a short time (minutes,
NOT hours or days) so that all readily exchangeable postions become
occupied by NH4+.  Any that hold onto another cation too tightly to
exchange with ammonium over this short period are not counted since
the site is not readily exchangeable.  Then they leach it with a 
different cation and see how much ammonium is leached out.  The measured
CEC depends on what two cations are used and the amount of leaching time,
so it's not precisely defined, but I would assume that the published
values don't depend on which cations are used much or else the numbers
would be useless (or they would have at least mentioned it!).  Also, it
is supposed that the exchanges take place at most on the order of seconds,
so that equilibrium is obtained very quickly.  If an exchange takes hours
or more, it's not included in the CEC, I believe, but is counted as a 
"fixed" position.  I know you know this stuff better than I but I thought
I'd explain since your question might be misinterpreted.  Anyway, in light
of the above I know what you suggest is still a possibility but I think
a high CEC will be better and more "natural" than the plain sand/gravel
mixures most folks use (for the majority of plants).  Laterite also seems
to be way below what is found in the wild.

: Was there any discussion of this in the book you found?

Other than the fact that differning affinities exist, no.  There are
zillions of texts on soil science and I'm sure even some intro texts
give more than Brady.  However, they're all on terrestrial soils for
the most part so the overlap is only partial.

: Another way to cast the question is this:  "when do you have 'enough'
: cation exchange capacity for a planted tank?"

Of course the above is all in theory, and this question could only be
answered experimentally, and would likely differ wildly from plant
to plant.  I'm still not sure I see the danger of having as much CEC
as possible.  The only effect that was mentioned in Brady was the NH4 and
K fixation in vermiculite and smectites, but this is a reversible process
which just lowers the CEC somewhat since cations are fixed in previously
exchangeable positions (sort of like CEC but slower).  I mean, so what
if 50% of the charged positions are occupied by tightly held molybdenum?
In your water changes you replace the removed Mo and now there's enough
Mo to satisfy the high affinity spots and still have some for the sites
with no special Mo affinity.

Correct me if I'm wrong; I'm very interested in these issues, but this
is not my field.  I just ran into this info and thought I'd share it
since it's all interesting and a small fraction seemed to contradict what
I'd heard on the net.

Jim.

as possible.


[PLANT] Interesting results and advice

by jkelly-at-landau.ucdavis.edu (Jim Kelly)
Date: 24 Jan 1995
Newsgroup: sci.aquaria

[Editor's note: Jim's article was originally followed by an ``intro'' article, which seemed important enough to give its own page.]

Sorry about the long line lengths.

 
     Hello all.  This is Jim Kelly who posted last summer about the
possible importance of cation exchange capacity (CEC) of the substrate in
relation to nutrition of plants.  I have fortunately gained control of
some aquaria in the greenhouse/conservatory on our campus (UC Davis)
which in conjunction with my own tanks at home has allowed me to test
the ideas contained in the previous postings, along with other options,
experimentally.  The posting I speak of is in the WWW archive of
discussions.  I can say with confidence that I have grown beautiful
plants and think that I have a cheap and repeatable formula for setting
up plant tanks that will thrive and even grow difficult plants in our
hard and alkaline water (as always there are exceptions).  The successful
tanks were not always in line with the speculations about practical
applications in the previous posts, so let me summarize the failures
and successes.  Recall that vermiculite was highly regarded as having
the highest CEC of non-organic matter (which is true) listed in soil
science texts, and that I speculated that vermuculite might be an ideal
substrate component if it could be made to sink.  I set up a 55 gallon
with vermiculite only on the bottom, and #3 sand on the top (4" total).
This was not successful for whatever reason.  I attribute it to the
large grain size of the vermuculite, which does not allow intimate
contact between the root and substrate.  Plants which were thriving
in peatmoss and sand before replanting in the new tank grew VERY slowly
and algae grew on them profusely.  The tank had 4 40w full spectrum bulbs,
CO2 injection, micronutrient additions, and slow drip reverse UGF
substrate aeration.  Substrate aeration was turned off with no effect
(the substrate was quite porous anyway).  Then pond lily tablets were
added in small pieces in the substrate, since I feared my frugal fish
feeding methods were starving the plants of macronutrients.  This 
resulted in an explosion of growth,  plants outgrowing the algae by far.
The boom lasted about 3 weeks, and nitrate levels rose to 10 ppm from
their zero levels before.  However, I didn't add micronutrients during
this period (there was iron in the tablets) and started dying quickly 
after 3 weeks (growing tip just stopped, algae set in).  At this point
I began adding garden supply iron nightly, and the plants came back
(not luxuriously, but new buds currently continue to grow).  During this
period I also slowly lowered light levels to control algae (it worked).
The tank now looks OK, but I do not consider it successful.  I lost 
in using potting vermuculite, but began to recognize the potential 
of macronutrient fertilizer (I was previously paranoid of adding
nitrogen and phosphates from net discussions), and the necessity of 
maintaining iron levels (as I should have known).  I don't know if
the sudden rise to 10 ppm nitrates slowed the plant growth.
     Meanwhile I replanted a 10 gallon which had done poorly for 1.5 years
which had gravel-over-peat substrate, CO2 and mirconutrient fertilizers, and
no substrate aeration (actually Crypt. affinis and Ludwigia repens had
done fine, and all others poorly).  This time I used vermiculite mixed with 
Yolo loam (a local sandy loam) on the bottom, covered by #3 sand.  I pushed
pieces of the pond lily tablets into the substrate.  This tank was 
exceptional right from the start.  A pitiful group of E. tenellus literally
exploded into a grassy field, with runners shooting out all over the
place.  It looks like a small patch of the E. tenellus field in Amano's
book.  This was encouraging.  A pitiful Nymphoides aquatica which I moved
from the dying 55 gal. immediately put out giant underwater leaves
like those pictured in Schuermann's book (2.5" in diameter is the biggest).
L. repens shot up with HUGE leaves, requiring frequent pruning.  This was
my best tank yet, but I don't think the vermiculite has anything to do
with it.  (I should mention also that the nitrates measure zero no matter
how much of the pond lily tablets I have pushed into the loam).  
     I attribute this success to:  the fine soil fraction at the bottom
with some organic content which provides high CEC, intimate root contact,
and hold the fertilizer nutrients in the soil;  the pond lily fertilizer
tablets which contain nitrogen (both soluble and insoluble), phosphates,
potash, iron, and other stuff I can't remember (I'll post the contents
and brand name if you want);  persistent iron fertilization (lack of 
which I believe caused the temporary sharp downfall of the 55g when I
added macronutrients, despite the iron content of the lily tabs).  I have
confirmed the repeatability of the setup with other tanks at the
greenhouse (substituting plain sand for the vermiculite this time).
These tanks are lit by a MH light, but otherwise are identical setups in
various size tanks.  A notable suuccess is a HUGE A. fenestralis
(mad. lace plant), which is planted in a pot of pure loam with lily tabs.
One large leaf is about 1.5 feet long, and it has over 10 leaves now.

Below are some notes that I wrote for the many people that see the 
greenhouse tanks and have asked for advice on growing their plants.  It
is obviously written for beginners, and most is conventional net wisdom,
but there are notable differences and my own techniques as described
above.  Another useful bit of info I've learned is how to control algae:
check nitrate levels and lower lighting until algae is controlled (I
recommend having too much light and lowering the levels slowly by 
putting strips of toilet paper between the lights and the cover glass
very gradually while continually cleaning the plants and watching
how fast it grows back.  High light is almost always the cause, in
my experience, and the gradual lowering of light seems to controllably
and predictably lower all algae types (except possibly cyanobacteria)
resulting in a light level that is still acceptable to the plants.  This
is the best way I could think of to cleanly and continuously vary light
levels, though I'd love to hear other ideas).  Also are there any crucial
points in your opinion that I've left out?

(I should mention that it seems to me that substrate aeration is
not needed for the tanks that I set up, but they are all fairly
young.  The two-level substrate I use seems to allow an aerated space
on top with lower nutrients and a rich, fine grained low aeration
section on the bottom for those roots which care to penetrate.  I have
noticed that Crypt roots stay in the upper layer.)

Jim Kelly
jkelly-at-landau.ucdavis.edu
     



[PLANT] Interesting results and advice

by jkelly-at-landau.ucdavis.edu (Jim Kelly)
Date: 27 Jan 1995
Newsgroup: sci.aquaria


Neil Frank (Neil.Frank-at-launchpad.unc.edu) wrote:

: Regarding algae:
:  
: >> Problems are due to excess nitrogen and light.
:     Excess nitrogen may be indicator for other excess elements,
: like phosphates. They both come from fish food, and probably are
: both in the lily tabs.

I feed the fish almost nothing, so most likely it is from the lily tabs
if excess P or N is in the water.  The lily tabs contain phosphates and
"soluble and insoluble organic nitrogen" (much higher percentage insoluble
as I recall), among other things.

: >> There will always be some algae growing...the algae should be
: present only upon closer inspection, not on first impression<<
:     While this is true, it is possible to have so little algae
: that it is only visible on *very* close inspection <g>

I have never achieved such a good balance, and I think it would
be unreasonable to expect it to be possible for beginners, for whom
the suggestions are meant.  However I have seen pictures of tanks
with no visible algae, so it must be possible.  Do you think there
is a repeatable formula by which you could instruct others to 
attain such a balance on a very low budget and still have lush
plant growth.  I haven't seen one yet, but I'm open to any simple,
beginner-level additions to the instructions which would assure
greater success.

: >>... gradual lowering of light seems to controllably and
: predictably lower all algae types (except possibly
: cyanobacteria)..<<
:  
:     This suggests that all needed nutrients (macro and micro)
: are in excess, so that algae growth is related to light
: intensity. Instead of using tissue paper to attenuate 160 watts
: of energy, why not use 2 timers and limit the duration of half
: the lights.  Another strategy is to cause a depletion of one or
: more nutrients in the water, and provide it to the plants through
: the substrate. (But, see comment on iron below).

I'm pretty sure that I keep most nutrients in excess.  This seems to 
be the simplest advice for beginners rather than going for the
starvation-of-the-water-column method.  I prefer to have the
uniform top coverage of 160 watts (4 tubes) for my shape tank.  The
tissue paper was the only way to continually vary light level with
flourescent lamps that was simple and easy to change.  I haven't
seen any discussion on lowering light levels to the optimal levels
on the net, where we chant the mantra, "more is better".  When I set
up the "unsuccessful" tank I spoke of, there was no loam, no lily tabs,
and I didn't feed the fish anything.  There was no tissue cutting
down the 160 watts.  Needless to say the plants only did OK, but the
algae absolutely flourished.  Also there was quite a bit of 'hornwort'
in the tank.  The nitrates read zero, and I have a hard time believing
that there were even low levels of nitrate in the tank.  I had seen
several tanks with much less light where algae was not a problem, and
a friend suggested that if nitrates were zero, then light was the
problem.  I added layers of tissue and the algae came under control.
I have no way of testing for phosphates in the tap water but I was
certainly not adding them at the time.  I have since concluded that
the thread type algae I had would thrive no matter how pure I could
practically keep the water, and that by lowering the light continuously
they can be kept at bay in a predictable way.  In my opinion the
lower light option is beginner friendly, while the limiting nutrient
method is only for experts and is possibly ineffective against certain
algae types.

: can use less erythromycin than label suggests - this antibiotic
: will be effective against BG algae even at one half the dose for
: a single day's treatment.

I have heard this also.  I have only used the treatment twice and there
were no rises in nitrates or fish stress during the period using the
label's suggestions

: Regarding Fertilizer:
: >>Plants took off for first three weeks with new setup and lily
: tabs, but suddenly began dying....  after chelated iron additions
: [Security brand iron]...plants put out new shoots and came back
: nicely<<
:  
:     This in intriguing.  Evidently a nutrient depletion
: occurred.  Unless Security brand iron also contains other
: micronutrients (e.g. Zn, Mn, Cu) like other iron supplements, I

It contains only iron.

: would have to say that the iron was depleted.  A bit confusing
: though.  Why is iron not supplied by the soil (is 'Yolo loam'
: deficient in iron; many soils are iron rich) or by the lily tabs. 

This catastophe occured in a tank with no loam.  The tablets (which
contain Fe) were added to the substrate which was coarse and well
aerated.  I guess most roots didn't contact the tablets directly
and the unchelated iron in them couldn't exist freely in the water.
That's my guess, but adding iron made a definite turnaround.

: >>Even tap water contains soluble iron, but in the high O2
: environment of your aquarium , it quickly turns to rust which the
: plants cannot use<<
:  
:     The lower layer of the substrate (with the loam) should be
: anaerobic.  There, the iron is not oxidized and should be
: available in the form needed by the plants.  Are the roots of
: some plants not entering this zone for some reason.  Is it too
: anaerobic which makes it uninviting?   If the iron in the lily
: tabs is both soluble and insoluble, then some may leach out
: initially and then be totally consumed.  The remaining amount may
: be trapped in lower zone where roots may not be penetrating.  A
: more porous lower layer or some other method (e.g. substrate
: circulation, say with heating coils) could make it more habitable
: and allow for element to be present in substrate but absent in
: water column (a good algae control strategy).

Obviously heating cables are out of the question for beginners on
a tight budget, for whom my suggestions are intended.  I won't even
spring for a DIY set myself.  The tanks WITH loam have never 
encountered iron deficiency, but I've been pretty diligent about
adding iron since the aforementioned Fe deficiency was discovered.
All roots seem to be in the loam area except possibly the Crypts:
I can see the fine roots hovering at the boundary layer by the glass
in places.  They grow quite well though, with many new leaves and
runners.

: >>I add iron supplement at night, since it temporarily clouds the
: water<<
:     This precipitate is reaction with something dissolved in
:     water column.  If this is phosphate, and if phosphate is in
:     excess, then addition of iron is also removing something
:     undesirable.

I would be happy to know this.  I will try to add it to some 
distilled or DI water to se if the same cloudiness occurs, and let
you know.  The additive is powdery, so I thought that was the cause.

: >>Also, this brand leaves a film on the water surface<<
:     This is indication of iron consuming bacteria, perhaps
: meaning too much iron?

Actually I looked closely at it:  It is green and looks like a 
unicellular algae (too small for naked eye).:  

: Final comment:
: I would suggest saying something about substrate maintenance
: (e.g. vacuuming).  I do not recommend it, but I do not know what
: works for Jim.

I don't vacuum at all.  If stuff accumulates on the suface of the sand
then I siphon it off, but never put the siphon in the sand.

Jim



Vermiculite info

by nfrank-at-nando.net (Neil Frank)
Date: Mon, 28 Aug 95

I was surfing the net and found this reference to Vermiculite

VERMICULITE

ALSO KNOWN AS: Horticultural vermiculite

DESCRIPTION: A white, extremely light-weight granular substance, with
grains about 1/16" in 
diameter (No. 3 grade). It is formed when mica chips are heated and expanded
to many times the
original size. Contains some potassium, magnesium, and calcium which are
slowly released in 
soil. Construction grade vermiculite is larger, and is used for loose fill
insulation.

USE: Used in soil mixes to increase the water and fertilizer retention of
the mixture, as well
as to lighten and open it up. Considered a soil amendment and a rooting
medium as well as a 
mulch (Chapter 2).

USE TIP: It is a very light material, lighter than sand, which can be an
important additive 
to container soil mixes. Avoid adding to clayey soils.

from: <http://www.btw.com/garden_archive/1_soil2.html>


Webb-Kelly 29 gallon setup

by ac554-at-freenet.carleton.ca (David Whittaker)
Date: Fri, 4 Aug 1995

Below is a diagram and a description of a Webb-Kelly tank that I put
together one month ago. It uses a 30" x 12" x 18" aquarium fitted
with a 175 watt metal halide canopy. Does it work? Do bananas grow
in Costa Rica? More seriously, although the verdict will be out for
some time, all of the plants are doing well. The clump of microswords
cover half the tank, the c. wendtii have thrown off runners, and the
c. nevillii have turned red (maybe they're not nevillii).

      _
     / \
    [ ]\ \
 ---| |--\-\------------------------------------------------------
 |  | |    \ \                                         ________  |
 |  |L|     \ \                                       |________| |
 |  |I|       \ \_____________________________________|        |_|
 |  |F|        \__CO2________CO2________CO2____________CO2  o==|=|======
 |  |T|                                               |        |-|     =
 |  | |                                               |        | |     =
 |  |T|                                               |INTERNAL| |   +++++
 |  |U|                                               | FLUVAL | |   +   +
 |  |B|                                               |        | |   +   +
 |  |E|                                               |________| |   +   +
 |  | |                                                          |   + C +
 |  | |                                                          |   + O +
 |  | |                                                          |   + 2 +
 |  | |####################### GRAVEL ###########################|   +   +
 |  | |-at--at--at--at--at--at--at- CLAY & VERMICULITE & POND TABLET FERTILIZER -at--at--at--at--at--at-|   +   +
 |  | |####################### GRAVEL ###########################|   +   +
 |  | -----------------------------------------------------------|   +   +
 |__|_______________UNDERGRAVEL___FILTER___PLATE_________________|   +++++


A DIY CO2 generator is connected to an Hagen Fluval Internal Filter
via silicon tubing and a minitube connector. The effluent spout of the
filter is attached to a Hagen spray bar which is submerged. It angles
upward so that the far end rests on the top of the lift tube which
projects an inch above the water line. A fine hole is drilled at this
end of the spray bar to allow a minute quantity of water to fall into
the lift tube, then down and under the undergravel plate. This simulates
ground water seepage while avoiding the Dupla effect, i.e.. costly and
unnecessary financial outlays of dubious value. The Fluval provides
mechanical and biological filtration, and conveniently dissolves the
carbon dioxide. The spray bar provides water movement in the middle
region of the tank without the turbulence and surface agitation usually
associated with this power filter or with external AquaClears. Carbon
dioxide retention seems to strongly correlate with minimal surface
water movement. The substrate follows a suggestion made last year by
Jim Kelly. Garnish with trace elements and macronutrients as required.

Initially, the half-dead plants, sparsely arranged, and the bright light
resulted in lots of hair and spot algae. This is still a problem. The
inhabitants, six otocinclus and a SAM, have yet to be fed. Things are
filling in nicely now. If I were to redo the setup, I would arrange for
the spray bar to breach the lift tube at a downward angle about ten
inches below the surface of the water. This would allow for better
mixing of the water and carbon dioxide and less blow off. I might also
go with a finer gravel or beach sand.

Dave Whittaker                                        August 4, 1995


Why doesn't anything live in substrate

by George Booth <booth/lvld.agilent.com>
Date: Mon, 10 Jul 2000

> Date: Mon, 10 Jul 2000 11:40:02 -0600
> From: Charley Bay <Charleyb@Cytomation.com>
> Subject: RE: ?
> 
> I've given this issue a lot of thought over the years, and I've concluded
> that we CAN have things called "freshwater reefs", but they can't be
> a flora/fauna match with marine reef systems.  

I haven't seem anyone suggest a few of the more common things we can find in a 
FW substrate. 

1. Malaysian Trumpet Snails - unless, of course, you hate them and have a herd 
of clown loaches on guard. 

2. Tubifex worms - unless you don't feed them because you heard they carry 
diseases or if you have a herd of corys on guard. 

3. Kuhli loaches and other fish that borrow in the gravel. 

4. The ubiquitous nitrifying bacteria!


George Booth in Ft. Collins, Colorado (booth@frii.com)
  http://www.frii.com/~booth/AquaticConcepts 


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