Salifert Iodine Test Kit (Reef)Iodine is present in NSW (Natural seawater) in a very low concentration (0. 06 mg L or 0. 06 ppm). Iodine occurs as different species. Some of them are iodide, iodate and hypoiodite. Generally when we say iodine then we mean one or more iodine species without a clear distinction being made. NSW contains predominantly iodate and to a slight extent iodide. There is however a misconception among many hobbyists that iodide predominates in NSW. This is