Some Things you need to know about Iodine Supplements

Hi guyz,

A summary of the 2 articles from Reefcentral. If you want more details, i can browse through my chem textbooks for in-depth explanation!

Many macroalgae (for e.g. Caulerpa racemosa and Chaetomorpha sp.) grow more rapidly in the presence of iodine. The two predominate forms are iodate (IO3-) and iodide (I-). Together these two iodine species usually add up to about 0.06 ppm total iodine. Marine algae can take up iodide directly, and apparently do so preferentially over iodate.

The various forms of iodine have very different chemical properties, and they should not be confused with each other. In addition to the three forms mentioned above, aquarists also frequently encounter molecular iodine (I2). Lugols’ solution, for example, contains a mixture of I2 and I-. It is the I2 form in particular that is the basis for the widespread belief that iodine is “toxic.” The I2 form, and that form in combination with other forms, it is a potent antibacterial agent that has long been used for disinfection. The naturally occurring inorganic forms (iodide and iodate) have little in the way of antimicrobial activity, and therefore, less toxic.

A general list of “who uses iodine”:
Gorgonia and antipatharian corals (black coral);
Tunicates;
Sponges;
Worms;
Shrimp;
Soft corals such as Xenia.

Iodine in Marine Aquaria: Part I
Iodine in Reef Tanks 2: Effects on Macroalgae Growth

Have fun!