Advice on Ferrous Fumarate for DIY Iron

[Djmac]

Hi,

I'm having trouble sourcing Ferrous Gluconate based tablets locally (Australia) but I've found these Ferrous Fumarate tablets at a local Chemist chain (Chemistwarehouse, $8.99 AUD).

Is Ferrous Fumarate an acceptable substitute? (I've read all the threads I could find, and it looks like Ferrous Fumarate is more preferred than Ferrous Sulfate?).

Is there anything suspect in the other ingredients?

If this is all ok, would I mixed 65.7ml of RODI with one tablet to make the same strength as the original DIY recipe?

Cheers
Dave

 

[Randy Holmes-Farley]

That should be OK. Let the undissolved solids settle out and not dose them.

 

[Djmac]

Thanks Randy, I really appreciate your help.

 

[Randy Holmes-Farley]

You're welcome.

let us know how things work out!

 

[Djmac]

A bit of back story. I had this algae reactor on my tank and was growing chaeto very well (took my nitrates down to almost zero), transferred it to my sons tank and the chaeto was just melting away. He has very high nitrates and phosphates (100ppm nitrates according to a salifert test). A big difference on the two tanks is I do regular weekly water changes (about 10%), whereas my son doesnt. I was working on the assumption that he had low iron due to no water changes.

I've been dosing the iron fumerate solution to his tank at about 1ml twice a week. This photo is after about 10 days, just short of doubled in size. Its very dark green and looking a lot healthier compared to before. I havent had a chance to check his nitrates yet.

No ill effects noticed. I'm calling this a success so far.

Thanks again!

 

[hunterallen40]

@Randy Holmes-Farley not to change the subject too much... But what is your preferred iron source?

Is iron sulfate heptahydrate a good candidate as well?

 

[Randy Holmes-Farley]

@Randy Holmes-Farley not to change the subject too much... But what is your preferred iron source?

Is iron sulfate heptahydrate a good candidate as well?

IMO, a weakly chelated iron is best. It holds the iron a bit to reduce likelihood of precipitation, but not so strongly that it is not readily bioavailable.

I recommend a DIY using Fergon tablets from a drug store. Ferrous gluconate.

That said, the sulfate is likely ok. It probably binds to natural organics in the tank.

 

[hunterallen40]

IMO, a weakly chelated iron is best.

I've read that disodium EDTA can be used as a chelating agent, but am not sure if that could be used here for that purpose?

Thanks for the input!

 

[Randy Holmes-Farley]

I think it

I've read that disodium EDTA can be used as a chelating agent, but am not sure if that could be used here for that purpose?

Thanks for the input!

It may chelate too strongly to be optimal, IMO.

 

[hunterallen40]

I think it


It may chelate too strongly to be optimal, IMO.

Interesting. I've got some reading to do it seems .

Thank you for the answer!

 

[Randy Holmes-Farley]

This has more:

Chemistry And The Aquarium: Iron In A Reef Tank

Randy discusses iron and its usage in our aquariums.

reefs.com

In many cases of iron intended for the marine hobby, the product may not tell you what the iron is chelated with, in order to protect proprietary formulations. I don’t actually know if it matters too much. Very strong chelation by certain molecules will actually inhibit bioavailability by not permitting release of the iron without completely taking apart the chelating molecule, but I expect that manufacturers have avoided those molecules. EDTA and citrate, and some others, actually degrade photochemically, releasing small amounts of free iron continually. It is believed to be the free iron that is actually taken up by many organisms, and likely iron(II), though some organisms may be able to convert iron(III) to iron(II) before uptake (the detailed absorption mechanisms are generally not known). There is a more detailed discussion of this degradation and uptake in “Captive Seawater Fishes” by Stephen Spotte (1992).

 

[hunterallen40]

Very strong chelation by certain molecules will actually inhibit bioavailability by not permitting release of the iron without completely taking apart the chelating molecule, but I expect that manufacturers have avoided those molecules.

So if the chelation is not broken down, it will not be bioavailable? Makes sense.

EDTA and citrate, and some others, actually degrade photochemically, releasing small amounts of free iron continually.

So EDTA and citrate make decent chelating agents for this specific setting (i.e. a well-lit one)?

Are there downsides that you know of to using one of those?

There is a more detailed discussion of this degradation and uptake in “Captive Seawater Fishes” by Stephen Spotte (1992).

Definitely will put that on my list of things to read, thanks!

 

[Randy Holmes-Farley]

To be honest, I do not have any info on the topic of iron chelation and bioavailability in a marine aquarium beyond what was summarized in the article and which came from Spotte’s book. It might not even be true, but in case it is, I think a weaker cheater is a better option and it seems to work perfectly well.