21mm Bio Balls Aquarium & Pond Filter Media Quantity?:100 BioBalls useful cleaning bacteria are not

useful cleaning bacteria are not affected

For an efficient biological filtration

Extra depth front to back for amazing aquascaping possibilities

and the included crystal sand media

21mm Bio Balls Aquarium & Pond Filter Media Quantity?:100 BioBalls useful cleaning bacteria are not21mm Bio Balls Aquarium & Pond Filter Media Premium Bio Balls Standard 21mm Filter media forms an essential part of any aquarium or pond filtration system. Our 21mm Bio Balls provide a large surface area for bacteria to develop, helping to break down ammonia and nitrite. Bio Balls also help improve overall water quality by maintaining healthy oxygen and PH levels, and absorbing and breaking down poisonous ions. Long lasting and highly effective, our