What do you use to dose Iron?

[Randy Holmes-Farley Verified Community Expert]

Understanding is the key to dosing and testing plays a small part! IMO

How would chelated Iron affect our chemistry? We have available many hydroponic products, but not comfortable with the long word that make the element chelated!?!

It is a complicated question in a reef tank.

IMO, you want a weak chelator, but a strong one or none is probably better than dosing no iron if you are growing significant macroalgae.

Totally unchelated iron added to seawater without organics will precipitate fairly rapidly and may not be useful. But reef tanks have significant organic matter than can naturally bind iron and hold it in solution, just as happens in the ocean. If you go this route, Fe++ (ferrous) iron is probably better since it is naturally more soluble in seawater. Fe+++ (ferric) iron precipitates faster into ferric hydroxide/oxide.

Iron chelated with a very strong chelator (like EDTA) is largely unavailable to organisms until it begins to break down in UV light. How well that happens may depend strongly on the lighting you have.

That's why I suggest a weaker chelator, such as gluconate, hence ferrous gluconate in the Fergon.

This has more:

Chemistry And The Aquarium: Iron In A Reef Tank ? Advanced Aquarist | Aquarist Magazine and Blog

Chemistry And The Aquarium: Iron: A Look At Organisms Other Than Macroalgae ? Advanced Aquarist | Aquarist Magazine and Blog

 

[KDawg0623]

OK, that won't impact algae growth, except as you remove solids before they decay and provide nutrients to algae. That's a good thing.

Thank you, Randy! I knew eventually I could get something right lol

 

[Randy Holmes-Farley Verified Community Expert]

Thank you, Randy! I knew eventually I could get something right lol

Just be sure too change the floss pretty frequently, otherwise people call it a detritus trap that just holds it as it breaks down.

 

[KDawg0623]

Just be sure too change the floss pretty frequently, otherwise people call it a detritus trap that just holds it as it breaks down.

Yes sir. Ours gets pretty blocked up within 5 days or so

 

[Mattm83]

I use and recommend ferrous gluconate as a DIY using Fergon tablets from a drug store.

Dissolve a tablet in about 20-50 mL of RO/DI and use this for dosing.

Hi Randy. In Australia ferrous gluconate isn't as easy to come by. Can I use ferrous sulfate?

 

[Mattm83]

I use and recommend ferrous gluconate as a DIY using Fergon tablets from a drug store.

Dissolve a tablet in about 20-50 mL of RO/DI and use this for dosing.

Can I use ferrous sulfate instead of ferrous gluconate. Harder to get fergon here in australia

 

[Randy Holmes-Farley Verified Community Expert]

Yes, but it may not stay in solution as readily. That's what I meant by unchelated iron being better than no iron. I've never seen any data on how fast iron is lost due to nonbiological processes, and it may bind to organics in the water and stay dissolved long enough to be adequate.