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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 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++