Re: Iron supplementation with chelated powder

> From: Mark Reineke <aa558 at sfn_saskatoon.sk.ca>
> Date: Thu, 4 Jan 1996 14:51:19 -0600 (CST)
> Subject: Iron supplementation
> I would like to try adding iron to a low-tech planted tank.
> I have some iron chelate powder (13.2% Fe, 68% EDTA).  Is this
> an appropriate iron supplement?  How does one calculate the dosage?

I'm not a chemist but I will try to answer this question. By
the way, there is an article by Jim Kelly in the latest issue of
TAG which covers DIYS fertilizers and very, very low budget 
aquarium setup. It describes the vermiculite/soil substrate with
pond fertilizer tablets.

Let's assume that you want a desired Fe concentration of .1 ppm
or .1 milligrams per liter. For each 100 liters of water that 
will be 75 milligrams of the 13% iron chelate powder. This is
too small to measure accurately without lab scales so what you
can do is prepare a solution of 1 gram of powder dissolved in
1 liter of distilled water. Use 75 ml. of the solution
for every 100 liters of water. Keep the prepared solution in
the fridge. BTW, I think it's probably toxic so make sure children
don't accidentally drink it. I'm assuming that 1 gm of the
powder will completely dissolve in a liter of water; is that valid?
I presume so since the dosages for Flourish and other solutions
is measured in 1-2 ml.

The next question is how fast is soluble Fe oxidized to an
insoluble form? I think it happens fairly quickly however the
actual concentration needed by plants is much lower than .1 ppm.
I think if you dosed to .1 ppm once a week you'd be ok. 

George, does the daily dosage for Dupla drops aim for a .1 ppm
concentration or somewhat lower?

Steve Pushak       spush at hcsd_hac.com     Vancouver, BC
(where it never stops raining... Aaarrggghhh! glub-glub)