200 Disc Air Stone is a large 200mm heavy duty sintered disc air diffuser that delivers a powerful and wide curtain of fine oxygen bubbles across its 8 inch surface for maximum oxygenation of large fish ponds and commercial aquaculture systems. With a jetting volume of 28 litres per minute, the 200 Disc Air Stone is one of the most powerful and efficient pond diffusers available to Nigerian commercial fish farmers who need serious oxygenation capacity from a single disc.