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Seachem Flourite


  1. Flourite v. Profile
    by Greg Morin <greg/> (Wed, 25 Nov 1998)
  2. Flourite/Flourish Tabs
    by Greg Morin <greg/> (Wed, 2 Dec 1998)
  3. Flourite substrate
    by Greg Morin <greg/> (Wed, 2 Dec 1998)
  4. Flourite and complex substrates
    by "James Purchase" <jpurch/> (Tue, 12 Jan 1999)
  5. (No Title)
    by ()
  6. Flourite and complex substrates
    by Greg Morin <greg/> (Wed, 13 Jan 1999)
  7. Flourite
    by Sherlock Wong <wong/> (Thu, 14 Jan 1999)
  8. Re:Flourite
    by Greg Morin <greg/> (Thu, 11 Feb 1999)
  9. flourite
    by Greg Morin <greg/> (Thu, 11 Feb 1999)
  10. surface area of clay and crushed fired clay
    by Greg Morin <greg/> (Tue, 16 Feb 1999)
  11. Flourite
    by Olga Betts <sae/> (Sun, 24 Oct 1999)
  12. RE:Bleaching flourite.
    by "Thomas Barr" <tcbiii/> (Fri, 12 May 2000)
  13. "Black" flourite
    by "James Purchase" <jpurch/> (Thu, 7 Sep 2000)
  14. FW: "Black" flourite
    by Greg Morin <greg/> (Wed, 13 Sep 2000)
  15. Washing Fluorite
    by "Michael" <Michael/> (Tue, 11 Dec 2001)
  16. Onyx vs Flourite
    by "James Purchase" <jppurchase/> (Mon, 22 Oct 2001)

Flourite v. Profile

by Greg Morin <greg/>
Date: Wed, 25 Nov 1998

> Greg Morin, can you say something about the advantages of Flourite over
> Profile (calcined clay from the makers of Turface, a baseball park
> conditioner)?

We don't have any direct experience with Profile so I really can't comment 
on the aspects you are probably most interested in. All I can really give 
you is second hand information that may or may not be totally accurate... 
you would have to verify with the manufacturer. What I have heard is that 
the material Profile is made from has also been used as kitty litter and is 
a manufactured material (i.e. not mined from a natural source). Whether 
this is good or bad within the context of using it in a planted aquarium is 
certainly open to discussion...

Since we don't have any real experience with Profile I can't really 
classify the following as advantages of Flourite over Profile, only as some 
of the important features of Flourite.
Flourite is a naturally mined porous fracted clay substrate that is rich in 
iron (mainly ferric). It obviates the need for laterite without really 
competing against laterite; laterite is a gravel bed supplement, whereas 
Flourite is a gravel bed substrate itself that is sufficiently rich in iron 
that it does not require supplementation. Based on our experience and the 
reports we have received from customers the material brings on a noticeable 
improvement in plant growth/response.

- -Greg Morin
Gregory Morin, Ph.D.  ~Research Director~~~~~~~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM

Flourite/Flourish Tabs

by Greg Morin <greg/>
Date: Wed, 2 Dec 1998

> 1)  I was once told by a pet store employee that flourite contains
> 'low-level toxins, which wouldn't affect fish, but which amphibians absorb
> more readily through their skin'.  Any truth to that?

This is a rumor that we have recently become aware of, although this is the 
first time I've heard it in relation to somehow affecting amphibians. We 
have factual evidence that the source of this rumor is a competing 
manufacturer who claims to have had Flourite analyzed. This manufacturer 
refuses to divulge who analyzed the material. The manner in which it was 
analyzed reveals a "dirty tricks" ulterior motive; they were looking to get 
us into trouble with the EPA, and when they couldn't (because apparently 
the results were below EPA limits) they have "unofficially" used this 
information out of context to make it appear that somehow Flourite is 

If you happen to know the employee's name and how we could contact them, we 
would be interested in finding out where they heard that information 
(especially if the source was a representative of the manufacturer in 
question). We would have no qualm with the employee (you're not going to be 
getting anyone in trouble), we just want to know where they heard that. 
Please contact me off the list if you know.

> 2)  Along similar lines as the flourish iron question that was raised, are
> flourish tabs supposed to be used in combination with a flourite gravel bed?
> Are the tabs similar, in the sense that you don't 'need' them, but might
> want to use them, to stimulate a plant that just needs that extra 'oomph'?
> Or is it really designed to enrich a non-flourish gravel bed?

Yes, the tabs are similar, you don't "need" them but are good for giving a 
plant that might need it a little extra something. In a non-enriched gravel 
bed they would have a much greater benefit since the bed presumably has 
very little nutrient content.

- -Greg Morin
Gregory Morin, Ph.D.  ~Research Director~~~~~~~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM

Flourite substrate

by Greg Morin <greg/>
Date: Wed, 2 Dec 1998

> Again, Greg, I don't want you to think I'm picking on you, but do you have
> any idea _what_ kind of susbtrates your product is being compared with?  If
> it's plain gravel susbtrates, we know that almost anything is an
> improvement.  Even kitty litter ;-)  I was wondering if you know how your
> substrate compares with laterite or other commercial substrate additives.

Well, in the example I gave, no, I don't know what substrate they had been 
using before... but that's a good point, if I get any similar compliments 
in the future I'll be sure to ask...

First I just want to say that Flourite is not marketed as a substrate 
additive, it is intended to be used as substrate or at the most a 50% 
cut... it competes with laterite and other substrate additives only insofar 
as it obviates the need for them. With that said, with respect to amount of 
provided iron, depending on which substrate additive you are comparing to, 
Flourite compares at least equally well if not a little better in some 
cases. The main advantage with Flourite is that because it is the substrate 
you are assured of maximum effectiveness through maximum contact whereas 
with a substrate additive the contact might be patchy if not well 
distributed. It is also my understanding (I haven't actually worked with 
the stuff myself) that laterite can be quite messy, falls apart, clouds up 
the tank when working on the substrate, then is difficult to remove if you 
want to replace it.

> Also, just from curiosity sake, and I know you can probably only speak for
> Seachem, but do manufacturers do their own comparison tests between their
> products as they are being developed and other known products?   If the
> only comparisons are between nothing, and a particular product, you've got
> a pretty good chance of getting a better response by adding much of
> anything.

Yes, I can only speak for Seachem :-). But for us, it depends on the 
product and what kind of claims we make. If we claim that such and such 
product performs better than so and so products, that is based on testing 
we have actually done in house. These performance comparisons are based on 
hard measurable data (e.g. our Matrix Carbon releases the lowest level of 
leachable phosphate, we just measure that in comparison to all other 
carbons, only one variable, very easy to establish a clear difference).

On other products where we don't make direct comparison claims, (like with 
Flourite or Flourish Iron), we just make sure the product performs as it 
should through our own testing, e.g. it wouldn't be wise to put on a label 
"Makes your plants grow 50% more than if you used Product X" as we all know 
from an ongoing thread that it can be very difficult to  control every 
variable and quantitate such things.

- -Greg Morin
Gregory Morin, Ph.D.  ~Research Director~~~~~~~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM

Flourite and complex substrates

by "James Purchase" <jpurch/>
Date: Tue, 12 Jan 1999

Kelly Beard has a problem with black BGA in her tank, which has a Flourite

> Anybody seen black BGA before?   Very unsightly.  I thought that maybe
> because the substrate is Flourite might have something to do with it.

Yes, I have seen BGA which has a black color (at least black to _my_ eyes).
But I seriously doubt that your Flourite substrate is the cause of it's
presence, or even contributing to it's growth. I have a tank using 100%
Flourite as a substrate and it is supporting beautifully growing plants with
no problem algae to speak of.

And Justin Colin wants more info on Flourite -

> What is Flourite made of,
> anyway, and, other than the obvious corporate interest, why does
> Seachem recommend not
> using it with any substrate additives?

Where is Greg Morin when we need him? <g>

As far as I know Justin, Flourite is a fired calcined clay (put "calcined
clay" into a web search engine as a search term and you will soon learn more
than you need to know about the properties of this material - I even came
across several archived posts where Steve Pushak was recommending Dupla
products over the use of soil in the substrate for beginners!!! <g>)

(No Title)


"When fired at high temperatures, some clays, fuel ash, and shales form
stable compounds that possess low bulk densities and internal porosities of
40-50%. Though calcined clays alter the physical attributes of media in a
positive way, they also decrease the level of water-soluble phosphorus in
the mix. Because calcined clays are characterized by a high cation exchange
capacity, fertilizer application rates may need to be modified if calcined
aggregates are incorporated into the media mixes (Bunt, 1988)."

There are a number of products which are commercially available which are
composed of calcined clays - Flourite just happens to be one of them, and it
is one which has a "form factor" which makes it ideal for our purposes in
aquariums. Other products, like Turface (much used by bonsai growers) might
also be suitable, although I have never seen it "in the flesh". Profile
Aquatic Soil is supposed to be another variant of a fired calcined clay
designed for use in ponds and water gardens, althought I gather that it is
formed into small "pellets" and so doesn't _look_ as natural and realistic
as Flourite (I got this info from the archives, again, I haven't seen it "in
the flesh"). Isolite is another "formed" product which I suspect could be
used in an aquarium substrate.

Based upon my experience with Seachem products in an actual working
aquarium, nothing else is _required_. The Flourite substrate, at least when
complimented with appropriate additions of Flourish and Flourish Iron, seems
to _me_ to be more than capable of providing lush plant growth. Another
case, I guess, of the fact that there are "many roads to Rome". You can get
a great substrate using laterite mixed with plain gravel or you can use a
substrate of fired calcined clay. Note that in _both_ instances, additional
nutrient supplementation via things like Duplaplant and Duplaplant 24 or
Flourish and Flourish Iron is required to complete the picture. But on the
other side of the coin, I don't think that Flourite and laterite are
mutually exclusive - I really see nothing wrong with using them together, I
just don't think that it's necessary.

The archives are full of annecdotal evidence which leads me to believe that
too much of a good thing is probably worse than not enough (despite what
Martha Stewart might have you believe). I am not Shakespeare and my
aquariums are no longer treated like the opening scene of "MacBeth" (bubble,
bubble, toil and trouble). Simpler is better. Sort of like the Meis van der
Rohe School of Aquatics - "less is more".

James Purchase
Toronto, Ontario

Flourite and complex substrates

by Greg Morin <greg/>
Date: Wed, 13 Jan 1999

> And Justin Colin wants more info on Flourite -
>> What is Flourite made of,
>> anyway, and, other than the obvious corporate interest, why does
>> Seachem recommend not
>> using it with any substrate additives?
> Where is Greg Morin when we need him? <g>

Hmmm... how'd I miss that one :-) In any case you answered this quite 
well James. I would just add, we don't recommend mixing Flourite with 
(a) other plain gravel and (b) laterite for the following reasons:

(a) we don't recommend it, but we also say if you are going to mix 
it, any such mixtures should be at least 50% Flourite and this is so 
the user gets at least a minimal benefit from using the Flourite...

(b) like James said, you can use laterite with Flourite if you want, 
but there really is no reason to, you're just wasting money on 
laterite since the Flourite provides a vast excess of iron to begin 

- -Greg Morin

Gregory Morin, Ph.D.  ~~~~~~~Research Director~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM


by Sherlock Wong <wong/>
Date: Thu, 14 Jan 1999

One of the key benefits of using Flourite alone is that
you can stir it up, and it does not cloud up the water
too much. This is great for maintenance, you can vaccum the
gravel without creating a mess.

Also, Flourite alone is quite nice looking, so
why mix it with something that will spoil the looks?

S. Wong


by Greg Morin <greg/>
Date: Thu, 11 Feb 1999

> Dr. Morin, could you please comment on this? You stated at one point I
> believe that Flourite was a naturally mined material. Is it subjected to
> high heat (fired) during processing (to increase internal pore space I would
> assume) or is it just cleaned, crushed and bagged?

Well, I can't say too much without getting in trouble ;-)

All I can say is, the material has experienced high levels of heat. 
It is naturally mined. And the order actually would be crushed, 
cleaned, and bagged ;-)

Hope that helps, but I can't really say much more without giving away 
a little bit of the "secret".

- -Greg Morin

Gregory Morin, Ph.D.  ~~~~~~~Research Director~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM


by Greg Morin <greg/>
Date: Thu, 11 Feb 1999

> Flourite is in all the mail order catalogues. I've been trying to get
> some from Pet Warehouse and That Fish Place, but they haven't been able
> to get any in for almost a month. I finally found some from Pet
> Solutions. They had some in stock.
> Is it that popular that Seachem can't make enough?

I'm having my sales manager look into the availability problem... 
there should not be one... but as I was gently reminded today, don't 
forget your LFS, they may very well be able to get it much quicker 
and if enough people ask, they will carry it all the time.

To the second questions, Yes, we can make enough, but just barely ;-) 
It is _extremely_ popular... it just flies out of here.

- -Greg Morin

Gregory Morin, Ph.D.  ~~~~~~~Research Director~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM

surface area of clay and crushed fired clay

by Greg Morin <greg/>
Date: Tue, 16 Feb 1999

> I made a typo in my last posting; I meant to ask Greg about the possible
> organic content of Fluorite not laterite! OOPS! :%)

I was wondering about that ;-) There should be no organic content in 
Flourite... all components are inorganic. Iron is the main nutrient 
provided, there may be a few others in lower levels, but like I said 
in my previous message we haven't tested for any others so I can't 
guarantee their presence either way.

> My speculation (guess) at the composition of Fluorite is based solely on
> the premise that a "good" substrate -might- contain all macro and micro
> nutrients in appropriate dosages. As for calcium, you might be reasoning
> that it should not be present because it would necessarily be in the
> form of a carbonate salt which would raise the pH. It could also be in
> the form of a sulphate which has lower solubility (I think) which won't
> have much effect on pH. I'm not at all sure that one could depend upon
> the substrate for adequate long term supplies of K, Ca and Mg.

Exactly. Even if we did add all of these components they would not 
last very long... i.e. after your initial level of calcium, potassium 
or organic nutrients were used up you'd have to (a) add more 
substrate (which gets to be pretty silly after a while) or (b) use a 
supplement. Well, since everyone already uses supplements why go 
through all the hassle of adding all of these components to a 
substrate when they are just going to be used up completely in a 
month or two at the most. The iron in Flourite is different, it's 
already in the material and in such high levels one really could do 
away with iron supplementation (for some species) and be just fine... 
i.e. the plants extract the iron directly from the Flourite through 
their roots, none is released into the water column.

> On the
> other hand, adding those minerals to a prepared substrate material would
> be easy

not as easy as you might think ;-)

> and might have benefits especially if they were not supplied
> adequately in the water as is often the case with potassium.

But the benefit would be transitory at best. We wouldn't want to add 
these type of components unless we could guarantee how long they 
would be released and at what levels... and right now we can't do 
that... the iron is the only component we make guaranteed claims 

- -Greg Morin

Gregory Morin, Ph.D.  ~~~~~~~Research Director~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM


by Olga Betts <sae/>
Date: Sun, 24 Oct 1999

>Date: Sun, 24 Oct 1999 07:54:28 -0700
>From: "Michael Rubin" <michael at>
>Subject: Flourite
>> I am tearing down my overly gross and neglected 55g plant tank.
>> Does or has anyone used Flourite as a sole substrate? Any idea how much I
>should use?

I use an all Flourite substrate in a 33 gallon. It looks great and grows
great plants. However, if your tank does develop algae I have found that
the algae (all kinds) likes to grow right on the Flourite. I presume this
is because it is a porous substance. I don't have algae anymore but when I
did having it grow on the substrate was a pain.

in Vancouver

>Date: Sun, 24 Oct 1999 11:06:25 -0400
>From: "Simon Frank" <>
>Subject: Re: Flourite

>Also, to go on a tangent, rinse the stuff VERY well.  Even though it is
>prewashed it is very dusty.  And then, even after rinsing it VERY well, it
>will probably still cloud your tank for a while initially, and everytime you
>go scrounging around to plant stuff.  It should settle within a couple of

I rinsed the Flourite a little and it was cloudy but that lasted such a
short time it was no problem. A little puff of "cloud" does come up if you
uproot a plant but mine settles almost immediately... it certainly doesn't
even take one hour let alone two...more like 10 minutes. Maybe it makes a
difference what one's water parameters are or how much current is in the
tank. Anyway, this has never been a problem for me and trying to rinse the
Flourite clean or even almost clean is not going to work.

in Vancouver

RE:Bleaching flourite.

by "Thomas Barr" <tcbiii/>
Date: Fri, 12 May 2000

>Hey all,
>Would bleaching Flourite destroy its chemistry and render it useless in 
>regards to its
>iron-bearing property? In the past, my tanks developed brush algae.  I am in 
>the process of setting up a new tank from scratch, making sure to bleach 
>everything (plants, gravel, equipment, etc...).  I tossed out the previous 
>substrate and have decided to go with a half Flourite / half gravel 
>substrate combo, but the more I think about it, I am leaning toward a 100% 
>flourite bed. In the event that the brush algae begins to grow over the 
>Flourite, I would want to eliminate it asap, and from experience, only 
>bleaching can do this (although I've heard of starving it to death which 
>I've never observed). Any comments?

Don't do it. On anything porous for that matter. Hard as hell to get it all
out afterwards. Use SAE's- they will eat BBA. 1 per ten gallons should be
fine and add them from the start and don't feed them very much. Work on
getting the fish load down and maintaining your Ph/KH in a good range. I
haven't had BBA on Flourite but have had it on sand. The same thing applies
for that also. Or any BBA issue. You cannot starve BBA BTW. It will hang on
for months and months. Often, high flows will cause some BBA to appear near
these areas such as spray bars etc.
Tom Barr

"Black" flourite

by "James Purchase" <jpurch/>
Date: Thu, 7 Sep 2000

Alex Ling asked:
"Anyone have any news regarding the pending introduction of black

Its called Onyx, and its been available for quite some time.

James Purchase

FW: "Black" flourite

by Greg Morin <greg/>
Date: Wed, 13 Sep 2000

>that these plans are on hold indefinitely. Apparently the source for the
>Black fluorite was a "vein" that they had come across while mining it. He
>said that it while it looked like they were going to able to mine
>significant quantities it turned out not to be the case. I even asked him if
>they had any Black Flourite lying around that I could purchase and he
>replied that he did not know of any. If anyone else has heard any new news
>on this front (Greg are you out there?) please reply as I am extremely
>interested in getting it when and  if it comes out.

This is basically the veins found to date are 
"contaminated" with too much red. We do not have any black flourite, 
not even small quantities, that would be availabe for sale. Believe 
me, we want to sell it as badly as you want to buy it... but right 
now it's a guesing and waiting game as to when that "perfect" vien 
will be found.

- -Greg Morin

Gregory Morin, Ph.D.  ~~~~~~~Research Director~~~~~~~~~~~~~~
Seachem Laboratories, Inc.     888-SEACHEM

Washing Fluorite

by "Michael" <Michael/>
Date: Tue, 11 Dec 2001

Enough of this lurking, time for me to post again!
After having arrived a day early at the recent AGA shindig in
Chattanooga, I found myself conscripted (along with Kevin von Finger) to
wash enough Seachem Onyx Sand to fill the bottom 3" of a 50g aquarium
for Mr. Amano's clinic, which was to occur 2 days hence.  And his
highness wanted the material washed AND DRIED!  This took several hours,
and involved more than a couple of beers.  As it occurred in a space
where other efforts were also underway, we enjoyed conversation with,
and the company of the lovely and talented Karen Randall and Charlene
Nash, as well as my fellow west coast maffiosos Steve Dixon and Erik
Not surprisingly, washing Fluorite was a lively topic of conversation
that afternoon.  Kevin and I lined a few bread trays with window screen
and rinsed countless gallons of water through the stuff with hoses.
This removed a lot of the smaller grained sand, which we collected and
stored, and forced us to wash even more of the raw material.  We filled
a 2-quart beer pitcher with water and dropped handfuls from each batch
into the column until there was no dust, then spread the mix out in the
sun to dry.
Here's the interesting part.  The general consensus, if memory serves,
is that, as dusty as Fluorite is, the dust is heavy and settles quickly,
making removing anything other than organic dust and wood chips
irrelevant.  No less an authority than Karen herself agreed that this
could be done with just a single quick rinse.  The material should then
be placed into a dry tank, and water added carefully so as not to stir
up the dust.  The point is, Fluorite and Onyx Sand are not coated, and
try as one may, there will always be some dust as the material rubs
against itself.
As always, your mileage may vary.
Michael Rubin ~ San Francisco, mid-50s and sunny 
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Onyx vs Flourite

by "James Purchase" <jppurchase/>
Date: Mon, 22 Oct 2001

I have tanks set up with both Flourite and Onyx and can honestly say that
whichever one you choose should be based on a combination of what your
tapwater is like and what "color" you like your substrate. Flourite won't
affect water parameters, Onyx will slightly increase both GH and KH, so if
you have really soft water, Onyx might be the better choice. Conversely, if
you have "liquid rock" coming from your tap, you might want to stick with
Flourite. But the effect of Onyx on water parameters is minimal, certainly
not like if you used crushed marble or limestone as a substrate. Toronto
water is moderately hard and I have both Discus and Dwarf Rams in the tank
which contains Onyx. The fish don't seem to mind (the Rams breed regularly)
the extra buffering.

Plants love both - if anything, I think that Onyx might even have the edge -
the tank with Onyx is an absolute jungle (of course, having 7 watts/gal of
MH lighting might help, a bit......).

Seachem definately has two winners on their hands with Flourite and Onyx

James Purchase

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