- Description Pond – Bio Ball Plastic – 2kg/160 When used effectively bio balls can provide an amazing source of biological filtration, great housing for the nitrifying bacteria crucial for the nitrogen Cycle. Features: – Open structure to create more surface area – Assists in converting toxic ammonia into nitrates – Perfect for freshwater or saltwater Specifications: – Bacteria friendly polypropylene 40mm – Large surface area What’s in the box 160 Bio Balls 2kg