Iron oxide, good or bad??

I have read alot that rust and the associated iron oxide leads to issues in coral growth. I have as yet not found any reason for this effect, as scientific as opposed to anecdotal evidence. I have however read that iron oxide can help in the metabolism of hydrogen sulphide as created in the sulphur cucle that all tanks go through
My questions are:1. Is there any scientific proof of the detrimental effects of irn oxide on marine life?
2. Does the presence of the iron oxide aid in hydrogen sulphide break down, or am I missing something or out of context? Hydrogen Sulfide and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com
3. Would the associated increase in iron oxide from something rusting cause there to be too much iron oxide in the closed system nd hence not be beneficial for the metabolism of the hydrogen sulphide?

Hope there is someone more learned than I am in this realm that can nail these and iron out some "old wives tales" if any.

Thanks to reefkeeping.com for the cool morning reading.
Neil

 

Someone correct me if I'm wrong but I'm sure iron oxide is used in a lot of phosphate removers, with out much detriment.

 

Have a look here this is what happens. They still have not recovared 100% yet.

Problem Pump - Marine Aquariums of South Africa

 

You're right Moz, Phosban is iron oxide based, but i think the way it is made stops the "rust" actually getting to the corals.

 

It is only made from a very high grade steel Mike, not our normal iron in the back yard

 

Does not seem very likely, steel is an iron alloy, so normal iron is purer.

 

Yip, I meant Iron, Afrikaans Translations