Nature's Ocean Hawaiian Puka Shells 6.8kg 3.5 - 5mm
Hawaiian Puka Shell is premium aragonite reef substrate harvested from the ocean floor, pre-washed and heat treated for convenience. The unique composition reduces nitrates, maintains pH and increases carbonate hardness. Ideal for aquarium tank bottoms, denitrifying anaerobic filters, and filter media with an extremely large surface area. Hawaiian Puka Shells has natural ocean Puka shells with a grain size of 3.5 to 5 mm