DescriptionDo you cultivate fish at home? Then you must need the nano balls tofilter the bad substance generated from the fish excrement or other badleaves. And these bad substance is not safe to fish, so you need thenano balls to resolve it and so your fish can safely live in your fishtank.Features- Color: random color. - Material: natural ore. - Size: 3.00X3.00X3.00cm/1.18X1.18X1.18in. - Optimization of culture capacity increase their practicality. - Enhanced water purification function for better use. - Increased service life, saving your cost to change them. - Hard and strong, not drop powder and slag. - It can decompose ammonia, ammonium nitrite, hydrogen sulfide and other heavy metal substances.