Nature's Ocean Hawaiian Puka Shells

Hawaiian Puka Shell #5 is premium aragonite reef substrate harvested from the ocean floor, pre-washed and heat treated for convenience. Its unique composition reduces nitrates, maintains pH, and increases Carbonite hardness. Ideal for reef system tank bottoms, denitrifying anaerobic beds, culturing live sand, and extremely high surface area filter media. Hawaiian Puka Shel #5 features natural ocean Puka shells with grain size ranging from 2.5 to 3.5 mm.