Warner Marine Research Concentrated Iodide Supplement Iodine is one of the most essential elements in marine and reef aquariums. It is critical for the formation of a variety of structures, including the skeletons and shells of many corals, clams, algae and other organisms. Iodide is necessary to keep corals colorful and healthy. Warner Marine Research Concentrated Iodine Supplement is the premier Iodine product available today. It is produced entirely from Pharmaceutical Grade (U.S.P.) Potassium Iodide, the highest quality raw material in the hobby. Inferior competing products are produced using poor quality raw materials containing up to 10x the heavy metals and impurities compared to Warner Marine products. Warner Marine Research is the only manufacturer to use these fine quality raw materials. It is also highly concentrated, making it highly cost effective compared to lower quality competing products. Warner Marine Research Concentrated Iodide Supplement is highly effective at adding high quality bio-available Iodide without the unnecessary impurities found in the competitor's products.