Iron sulphate and chloride mix for ionic balance?

[Cory]

I was thinking the best mix for iron would be equal in sulphate and chloride. Can I mix the two together for iron dosing so each dose is not going to mess up the sulphate and chloride?

 

[UK_Pete]

Hey Cory,

Went through this with Randy recently. Upshot is that iron sulfate or chloride would not be soluble in seawater, or would not stay in solution for any time. You need a chelate of iron, Randy used to use an iron citrate he posted the recpie for some time ago, but he now recommends ferrous gluconate IIRC, from fergon tablets easily available in the states.

The only iron tabs available to me in the UK had lots of stuff in them including phosphates and other stuff I didn't want so I made his old iron citrate mix. I ordered ferrous sulphate and trisodium citrate dihydrate from ebay for pennies, and mixed them according to his post, 25 grams ferrous sulphate, 50.7 grams trisodium citrate dihydrate, and 250 ml water. I mixed with a magnetic stirrer for a few hours but I dont know if thats really needed. 25 grams of ferrous sulphate has 5 grams iron in it, so that should allow you to work out the dosing (ie if your final mix is 300 ml, you have 5 grams iron in 300 ml water, so 5/300 = 16.6 mg iron per ml), in case you want to do this. The citrate is a weak chelate from what Randy has said, weaker than something like EDTA, so its more likely to release its iron to organisims which need it than a stronger chelator apparently.

 

[Cory]

Good to know! My purpose would be to dose this for po4, not so much for macro. Would it be ok?

 

[UK_Pete]

Read up the thread a few weeks ago from Glenn about his 'DSR' method, he is doing it and reports success. He says higher than 0.25ppm causes problems with some tank inhabitants, so sticks to 0.15 ppm max. He also says within a few hours of dosing the iron levels drop quite a lot, I guess from 'doing its job'. I also asked a few questions about this to Randy who provided some extra help, you can probably find it with the search (dont remember the thread titles). I have used it a little, but I overdosed inorganic phosphate recently so decided to stick with GFO to bring the bulk of the high phosphate down, but will probably use this in the future.

 

[Randy Holmes-Farley]

FWIW, there is so little iron added that any other ions in it are unimportant.

I don't think there is ever any reason to have detectable iron.

 

[UK_Pete]

I don't think there is ever any reason to have detectable iron

Randy, is that because you think liquid iron salts are not a safe / good / effective way to control phosphate, or is that just referring to nutrient requirements? Or do you mean its OK in your view to use it to control phosphate, but in that case keep it below detection limits?

 

[Cory]

Hey guys, thanks. Probably Randy doesn't want to raise anything too much over nsw levels. Nsw is a good stable certainty to follow.

Randy can you turn on your pm for a sec.

 

[Randy Holmes-Farley]

I was thinking as an iron supplement, but I'd also be a bit wary of keeping iron high for any reason. It is not entirely benign.

It undergoes something called Fenton chemistry, where the iron helps natural oxidants like hydrogen peroxide become more damaging to tissues.

Fenton's reagent - Wikipedia, the free encyclopedia