Fluval Sea Magnesium is a concentrated, magnesium-boosting compound formulated to elevate magnesium levels effectively, while not affecting the delicate ionic balance in marine water. This supplement supports optimal pH and strong coral growth as well as helps prevent calcium precipitation. Fluval Sea Magnesium contains high quality and ultra pure magnesium chloride, ensuring that you're getting a pristine product that's free of unwanted contaminates. It does not contain gluconates, nitrates, or phosphates.Fluval Sea Magnesium is strongly recommended for offsetting the ongoing depletion of magnesium caused by coral absorption.