Please explain the usage of Iodine

[kimha]

Hi,

I am going from FOWLR to fish with a little bit of corals. So far I learned that Alk, Cal, and Ph at the right levels are important. I went to buy some corals today and was told that I also need to add Iodine supplements if I have corals. Could some one explains the function of Iodine for corals, and is it absolutely necessary for a reef setup. If it is needed, what brand would you recommend?

Many thanks.
Kimha.

[Randy Holmes-Farley]

IMO, iodine is neither necessary nor useful in reef aquaria. I dosed it for years, then stopped completely when I realized that there was no evidence that anything that we keep needs supplemental iodine. Not shrimp, not xenia, not mushroom corals, nothing. All of those have thrived for many years in my system since stopping the supplemental iodine.

I discuss much more about iodine in these articles:

Iodine in Marine Aquaria: Part I
http://www.advancedaquarist.com/issues/mar2003/chem.htm

Iodine in Reef Tanks 2: Effects on Macroalgae Growth
http://www.advancedaquarist.com/issues/april2003/chem.htm