Python Multi-Purpose Bio-Clean breaks down organic waste in both freshwater and marine aquariums. This formula by Python helps reduce the time and effort you spend on aquarium maintenance by preventing and eliminating sludge build-up on filters, gravel, decorations, and other surfaces. Simple to use and fast-acting, Bio-Clean rapidly breaks down organic pollutants resulting from decaying material, overfeeding, and fish waste to promote a cleaner and healthier environment. The accelerated breakdown of organic waste may cause a temporary ammonia spike, so its recommended to use Multi-Purpose Bio-Clean in combination with Python Multi-Purpose Bio-Support to help prevent and control elevated ammonia and nitrite levels. Multi-Purpose Bio-Clean is Step 3 in the three step Python water treatment system, along with Pythons Multi-Purpose Water Conditioner and Multi-Purpose Bio-Support. This product is safe for use with aquarium fish, invertebrates, and plants. 67.6 fl oz of Python Multi-Purpose Bio-Clean treats 4,000 U.S. gal of water.