Hikari Phosphate Minus Pad (Blue) is a specialized chemical and mechanical filtration media specifically formulated to reduce phosphate levels in marine, reef, and freshwater aquariums. Designed to trap particulate waste while actively removing excess phosphate from the water column, it helps create the conditions required for improved water clarity, reduced nuisance algae growth, and overall aquarium system stability. By removing phosphate before it can fuel unwanted algae and negatively impact water quality, it helps support balanced aquarium ecosystems and long-term aquatic health. Easy to cut, install, and replace, and precisely manufactured for consistent results, Hikari® Phosphate Minus Pad (Blue) helps maintain a stable aquatic environment where fish, corals, and other aquarium inhabitants can thrive.