There are a few key components that work together to clean waste in a fish tank:
Mechanical Filtration
Mechanical filtration refers to physically removing solid waste and debris from the water. This is typically achieved through the use of filter media like filter floss, sponges, or foam blocks. As water passes through the media, large particles get trapped and removed from the water column.
Biological Filtration
Biological filtration involves beneficial bacteria that break down harmful ammonia and nitrite in the tank. These bacteria grow on surfaces in the filter and substrate. As waste accumulates, good bacteria convert ammonia into nitrite, and then into less harmful nitrate.
Chemical Filtration
Chemical filtration uses filter media like activated carbon or resin to remove dissolved organic compounds, odors, colors, and medications from the aquarium water. The media absorbs and traps these impurities as water passes through.
Substrate
Gravel and other aquarium substrates allow growth of beneficial bacteria that help break down waste. The substrate is also a place where debris can settle at the bottom of the tank.
Water Changes
Partial water changes help dilute nitrate and remove waste materials from the aquarium. Changing out 15-25% of the water weekly helps reset water parameters and replenish trace elements.
Algae Control
Controlling algal growth helps use up excess nutrients like phosphate that contribute to waste issues. Adding algae-eating fish like otocinclus or algae-grazing snails can clean glass and decorations.
Vacuuming
Using a gravel vacuum during water changes will suck up debris from the substrate. Target areas where uneaten food or waste collects.
Conclusion
Maintaining good water quality in an aquarium requires both mechanical removal of solid waste as well as biological filtration to break down dissolved compounds. Work together with filtration equipment, substrate materials, algae management and routine maintenance like water changes and vacuuming to achieve a clean, healthy environment for fish.