Bahamian Aragonite Aquarium Sand is the ideal substrate for marine, reef or African Cichlid aquariums. It is a pure Oolitic Aragonite sand collected from the crystal clear oceans of The Bahamas, with no harmful tar, organics or impurities. This aquarium sand has unsurpassed buffering capability and helps maintain a natural pH balance of 8.2 without the constant addition of chemicals. One kg of Oolitic Aragonite Aquarium Sand offers over 1 million sq. cm of surface area providing a huge space for housing ammonia, nitrate and nitrite reducing bacteria. This substrate is a fine sand comprised of calcium carbonate (aka aragonite). Calcium carbonate is a naturally occurring salt water component and can make water cloudy when disturbed. Calcium Carbonate also acts like a flocculant. Flocculants will help your filtration capture more particles, leaving you with crystal clear water as the cloudiness is filtered out. Also, any cloudiness is not harmful for fish and will resolve within a few hours/days of filtration. Over rinsing of this substrate is not recommended due to the chemical composition of aragonite. Oolitic Aragonite Sand is the ideal grain size for reef tanks, fish tanks, plenum systems and refugiums, but is not recommended for high flow aquariums that are SPS dominate.