PP Bio balls provide large living area to help the growrh of bacterial, Put it in a filter pond or tank, they can quickly reduce ammonia and nitrite to help maintain the healthy of aquarium tank, pond or fish farm water conditions and favour of fish and plants. Bio Balls are plastic spheres designed to greatly increase the surface area present in a wet/dry type of filter. The increased surface area creates a much larger area for beneficial bacteria to grow on, consequentlyincreasing the amount of biological wastes that the filter is able to process effectively.