Cheleated iron.

atoll · Sep 19, 2017

Hi Randy,
I am in the UK and have a 100gallon using an ATS for nutrient export. I am thinking of making an Iron supplement and have read Fe-EDDHA is a better form of iron to add with our high PH levels can you confirm this or otherwise? I found this on the bay and wonder if it would be suitable and if so how would you recommend using it and the amount to add please? Thank you.
http://www.ebay.co.uk/itm/Fe-EDDHA-...950478?hash=item1c8fa3a3ce:g:mLQAAOSwRLlZoZHq

Randy Holmes-Farley · Sep 19, 2017

I do not think that chelated iron in general is better. There are many types. Most are likely OK, but not necessarily better (IMO).

Some iron chelates (iron EDTA, for example) are so strongly held that organisms cannot get the iron unless the EDTA is broken down by UV first.

I generally recommend ferrous gluconate, which in the US is available at local drug stores under the name Fergon tablets.

You need not add much iron at all. Certainly not enough to detect. 1 ppb is plenty, once every week or so.

atoll · Feb 5, 2018

OOps for some reason I missed your answer soory about that and thank you for your answer.
I bought these https://www.ebay.co.uk/itm/3-x-Ferr...992027&hash=item282ff85f65:g:powAAOSwSlBY3kdm
and using them seems to be working as my Ulva had all but stopped growing but has picked up since adding the Iron. I made up 20ml of RO and crushed a tablet into it. Thanks once your advice, it proved invaluable once again.

Randy Holmes-Farley said:
I do not think that chelated iron in general is better. There are many types. Most are likely OK, but not necessarily better (IMO).

Some iron chelates (iron EDTA, for example) are so strongly held that organisms cannot get the iron unless the EDTA is broken down by UV first.

I generally recommend ferrous gluconate, which in the US is available at local drug stores under the name Fergon tablets.

You need not add much iron at all. Certainly not enough to detect. 1 ppb is plenty, once every week or so.