Key Features Single Air stone Sits in base of BiOrb Helps to diffuse water and create oxygen rich air bubbles. Simple to replace Replace every 3 -6 months biOrb Air Stone is a simple to replace stone, vital in the filtration process of your biOrb Aquarium. The airstone sits in the base of the biOrb underneath the filter cartridge. Its job is to help diffuse the movement of water and create the bubbles that flow up the bubble tube and disperse oxygen around the tank. Over time the tiny pores in the air stone can become blocked by dirt and lime scale preventing air from getting through properly. Replacing the air stone every few months will ensure your biOrb environment is kept to its best. Specifications 1 x Air stone
