There are many types of filtration systems out there available to help you maintain a cleaner fish tank. They can be categorized into three main types. Bio-filters, Mechanical filters, and Chemical filters. Although there are many more out there, we will focus on some of our favorites that fall under these categories.20 gallon fish tank with filter
Types of Filtration
Sponge filtration: sponge filtration uses a pump that draws air from outside the tank to push the tank water through a sponge which cleans the water of unwanted waste and debris by trapping it in the sponge. It is an excellent choice as the sponge allows for a healthy amount of bacteria growth that is essential for the break down of fish waste. It is an optimal type of filtration for tanks that are being used as quarantine for sick fish as they do not usually contain charcoal that can break down any medication that your fish may need. Sponge filters are also a great choice if you are breeding, as the sponge poses no danger of small fry being sucked into the filter. At the same time, the micro-organisms that grow on the sponge provide excellent nourishment for your fry. They are also easy to maintain and very inexpensive.
Under Gravel Filtration: Under gravel filtration is an excellent bio-filtration system that uses two tubes on each side of the tank. These tubes are attached to power heads or something similar to suck the water the water from the bottom of the tank up and then push it back down to bottom again causing the water to circulate in the tank from top to bottom then back to the top again. At the bottom of the tank lies a plate, grate or sponge. Gravel or similar substrate is then placed over the grate or sponge. When the water is pushed through the substrate, it filters the water trapping the debris in the gravel. Then you will vacuum the gravel to get rid of the unwanted waste. These filters are highly efficient and very inexpensive. However, they are not always the best choice alone for larger tanks but can be paired up with a hang on back filter.
Canister Filtration: a canister filter is a closed filtration system that typically sits beside or beneath your fish tank. Water is pushed through the canister leaving the solid waste and debris in the canister. Canister filters are your best option if you are dealing with larger debris. However this type of filtration requires more frequent cleaning. Typically every 2-4 weeks. You can significantly improve your filtration by placing a wet dry wheel at the outflow of the canister filter.
Power Filters: These are available as internal or external filtration systems. This means that the internal is in the tank and the external hangs on the outside of the tank. Because power filters use motorized pumps, the water flows at a much faster rate. Faster flow rates will dramatically improve the filtration of your tank. Internal power filters can be unsightly and hard to clean as you have to take them out of the tank where as the external power filters are easily accessed as they hang on the outside of the tank.
Activated Carbon: Activated carbon is a type of chemical filtration that you will want to use if you use if you are looking to get rid of foul odors or unwanted color in your tank water. Activated carbon is used to combat pollutants that biological and mechanical filtering can not as the pollutants are too small and easily slip through filters. These tank pollutants often come from fish medication, pollutants in the air as well waste produced by different biological processes. Activated carbon effectively absorbs unwanted chemicals and waste as well as detoxifying harmful gases. Use caution when using this type of filtration system as it will also absorb nutrients needed to sustain plant and invertebrate life.
As there are many options for your tank filtration, it is important that you do your research and choose the system that will be best for your tanks inhabitants.