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Re: Calculating Fe concentration

Thanks, but what I meant was not to achieve the 0.1 ppm target level, but to
raise the Fe concentration by 0.1 ppm, ignoring any Fe that might already be
in the tank. I just wanted to make sure that that's how it is calculated.
So is the free form of Fe the only usable form? And the chelated is not?
Alex R.

nature wrote:
> Alex R wrote :
> "...So if 1 mL TMG has 0.7 mg Fe, I need 11.3/0.7=16.2 mL TMG to
> increase the concentration by 0.1 ppm..."
> My response:
> IMO may not be that simple.
> Assume that TMG Fe content is 0.07% which is all the Fe ions bounded by
> chelators HEEDTA and DTPA as stated by TMG composition. (APD archive
> fertilizer by clc-at-hdc.hha.dk CLAUS CHRISTENSEN Date: Wed, 5 Jul 1995)
> At any time not all the chelated Fe dosed in the tank would decompose and
> release the free Fe++ immediately. It is a slow process depends on the
> lighting level, bacterial load, etc.
> The 0.1ppm target refer to the free Fe++ in the water at any one time.
> (reference : Dupla's book The Optimal Aquarium field data sampling). So
> amount of chelated Fe dosage should be higher.
> I would think that a correct method will be by actual Fe measurement,
> started with a low dosage level (Tropica suggest 1/2 the recommended
> and then slowly up the dosage amount while monitoring the actual Fe++