Kent Pro Clear Marine produces and maintains crystal clear aquarium water without affecting pH. Whereas competing products may clog the fishes gills, suffocating them, and cause invertebrates to close up, Kent Pro Clear is completely safe for all marine fish and invertebrates. Pro Clear uses a blend of high tech polymers that will safely flocculate any algae, dirt, bacteria or other cloudy water ca using part icle s. Contains no phosphates, nitrates, or silicates to cause undesirable algae or slime growths.