Airstone is a piece of aquarium furniture, traditionally a piece of limewood or porous stone, whose purpose is to gradually diffuse air into the tank, eliminating the noise and large bubbles of conventional air filtration systems, and providing other benefits to the health of the fish. Natural micro-pores in wood create incredibly fine bubbles. Ideal for Nano skimmers, air-driven protein skimmers, and foam fractionators. It can also be used as a premium air stone in any aquarium due to the sheer volumes of microbubbles these create once connected to an air pump. It effectively skims the waste materials off, thus preventing bacteria from decomposing these organic compounds to nitrate and phosphate. Moreover, it also helps to reduce the amount of harmful free-floating bacteria.