Three types of filtration exist on the market – biological, mechanical, and chemical. Varying experts will assert that you must utilize all three in your tank. For a marine aquarium with a reef environment, that may be good advice. There is no definitive answer on what combination is suitable for your aquatic environment. Educating yourself on the functions of all three will enable you to pick the filter(s) that will safeguard your fish and invertebrates’ natural habitat.
Biological Filtration
Biological filters are a must for every aquarium. They stimulate the growth of nitrifying bacteria that breaks down harmful ammonia to less toxic chemicals such as nitrate. It sounds simple enough, but how this is accomplished is quite impressive. A widespread method of producing these beneficial bacteria is adding fish to the aquarium. The bacteria, which ride on the fish, drop off and spread throughout the tank and grow. This also leads to increased amounts of dangerous ammonia, so it is important to add fish gradually. It can take several months to establish this cyclical process.
Aquarist believed that they had an easier, quicker solution in under gravel filters and crushed coral. Along with the water, detritus and junk was pulled through the crushed coral, which clogged the filter bed. Some fish enthusiasts have gladly replaced these under gravel filters with biofilters such as canister filters, trickle filters, bio wheels, fluidized bed filters, or sponge filters. These devices incorporate other methods of filtration making them even more useful. Other aquarists opt for the natural route to biological filtration using a mixture of live sand and crushed coral as the tank’s substrate.
Mechanical Filtration
Mechanical filters use a more direct approach to remove particulate matter before it decomposes and adds to the ammonia load. These filters are the most versatile since they can be used in most filtration devices. The key to their efficiency is regular cleaning. Otherwise, waste can accumulate and your effort is in vain. Aquarium owners must always be mindful of the flow rate of their device, which is automatically set to manufacturer’s standards. A reduced flow can lead to an unclean filter (or vice versa) and adversely affects the health of the entire aquarium.
There are a variety of mechanical filters on the market, each with its own advantages. The power filters’ low price, ease of use, and maintenance makes it the most popular of all mechanical filtration devices. These quiet devices can also be used for chemical and biological filtration.
Canister filters are equally as versatile. These large-capacity filters, which run on their own pumps, can be used for mechanical, chemical, and biological filtration. Many aquarists prefer the hang-on-tank canister filters to promote water quality, but there are a large variety of canisters styles available.
Wet/Dry filters, also known as trickle filters or bio-towers, are more suitable for fish-only tanks than reef systems. This is due to the biomaterial inside the filter’s wet/dry chamber that becomes dirty and results in a buildup of harmful nitrates.
Internal filters are a great option for smaller tanks. Their compact and simple design makes them easy to operate. As the name suggests, the filter runs within the aquarium and is powered by a small water pump, or air pump.
Protein skimming/foam fractionation is not mandatory, but it is a trusted method of maintaining water quality. Dissolved proteins linger to air bubbles and form protein foam. Protein skimming pumps the air bubbles through a small columnar removing the dissolved proteins from the tank.
Chemical Filtration
Particles are not the only thing floating in your aquarium’s water. Copper, ammonia, and phosphates also threaten the stability of your tank’s environment. Chemical filtration utilizes chemically enhanced products to treat the water. Activated carbon is the leading medium used. Others such as calcium hydroxide, zeolite, and even peat moss work as well.
Protein skimming, Power, Canister, and Internal filters are some of the most common filtration devices used for chemical treatment. Of course these double for mechanical filtration devices as well. Trickle filters are a popular choice amongst saltwater aquarium owners. The water is first drawn from the tank. Then, it is siphoned through the mechanical, biological, chemical, and auxiliary filters. Finally, it placed back into the aquarium.
To target specific chemicals, look to Reactors. Water is drawn through a canister-type chamber where it meets the chemical media. For even more effective filtration, they can be run pressurized.
The methods of keeping your aquarium’s waters clean are numerous. Using biological filters as a base, there is a wealth of combinations that you can build upon to create a healthy environment for your pets.
Copyright 2006
Reef Saltwateraquarium
