Whisper Power Filter 20 Whisper Power Filters Are The Best-Selling Brand Of Power Filters In The U.S. Appropriate For Every Size Aquarium, They Provide The Three Types Of Filtration That Your Aquarium Needs: Mechanical Filtration -- To Remove Particles Such As Uneaten Food, Bits Of Plants, Fish Waste, Etc., From The WaterBiological Filtration -- To Provide For The Growth Of A Colony Of Beneficial Bacteria That Will Eliminate Harmful Toxins In The WaterChemical Filtration -- Activated Carbon Removes Compounds That Cause Odors And Discoloration Of The Water .
Biological Filtration -- To provide for the growth of a colony of beneficial bacteria that will eliminate harmful toxins in the water
Chemical Filtration -- Activated carbon removes compounds that cause odors and discoloration of the water
Mechanical Filtration -- To remove particles such as uneaten food, bits of plants, fish waste, etc., from the water