Fluval Sea Trace Elements provides a concentrated blend of 11 key trace elements in naturally found proportions present in seawater. The supplement supports essential biological processes in marine aquariums. Fluval Sea Trace Elements contains high quality and ultra-pure trace elements, ensuring that you’re getting a pristine product that’s free of unwanted contaminates. It does not contain gluconates, nitrates, or phosphates. Fluval Sea Trace Elements is strongly recommended for offsetting constant depletion of trace elements caused by protein skimming, chemical filtration and ongoing natural biological processes.