Fluval Sea Iodine is a concentrated, iodine-boosting compound that's formulated with two naturally occurring iodine compounds found in ocean waters in the correct proportion. The supplement supports the growth and condition of corals and other invertebrates. Fluval Sea Iodine contains high quality and ultra pure calcium iodate and potassium iodide at the proportion found in natural sea water, ensuring that you're getting a pristine product that's free of unwanted contaminates. It does not contain gluconates, nitrates, or phosphates. Fluval Sea Iodine is strongly recommended to offset the rapid constant depletion of iodine caused by protein skimming, coralline algae growth, coral growth and oxidizing interaction