Types of Home Aquarium Filtration – by Lee Dobbins

It’s important to have good filtration in your home aquarium because the quality of your water is critical to the health of your fish. The better your filtration, the clear your water will be and the more fish will be able to keep while still maintaining good water quality and a healthy environment. There are three basic kinds of filtration commonly used in the home aquarium – biological, chemical and mechanical. Often times the filtering system will include two of these types of filtration combined. a good example is the typical aquarium filter that hangs on the outside of the aquarium with it to go into the water that sucks up the water, pushes it through a filter and some sport of sponge and returns it to the tank through the other side. This type of filter uses mechanical filtration as well as biological filtration.

Mechanical filtration: is pretty much what it sounds like, it uses mechanical means to filter particles and such from the water. This is your typical filter that has some sort of a pump which sucks the water in and some sort of a filter that the water passes through and then a tray or tube that puts the filtered water back into the aquarium. These can be the power filters that hang off the back of your tank in suck water up through a tube running through a cartridge before pouring it back into the aquarium, or under gravel filters that suck the water down through the gravel actually using the substrate as a filter and then return the water at the top of the tank.

Biological filtration is one that not a lot of people think about but it is very important for your home aquarium. The waste from your fish indicating pieces of money and food are constantly being broken down into ammonia which can be toxic in your fish tank. Biological filtration allows bacteria to keep this ammonia making the water safer for your fish. The thing is that this bacteria needs something to grow in. While the bacteria can grow right in the gravel bed, a lot of mechanical filters include a bio wheel or some type of media or a sponge that the bacteria can grow on.

Chemical filtration relies on the use of chemicals such as carbon or more new chips to absorb the ammonia In the water. Many power filters also come with a little carbon pack that you act to be with water and putting your filter in this carbon pack will be doing the job of chemical filtration. But the bacteria colony in your biological filtration should also be taking this so many people question whether you actually need chemical filtration in your home aquarium.

Aquarium filtration is vital for any aquarium but the size of your tank makes a difference as to which types of filters you use. If you are in doubt, your best bet is to ask the person at you’re aquarium store where you bought the fish tank and they are usually pretty well versed in what type of filters are best for the style and size tank you have. Maintaining your filter and changing the cartridges as recommended its key to having happy healthy fish and a beautiful crystal clear tank.

Which Aquarium Filters Are Right For You?

Undergravel Aquarium Filters

The most common aquarium filters for biological filtration are Undergravel Filters (or UGF). These consist of a pierced plate that is placed between the substrate and the bottom of the tank. It works by pulling the water through the substrate and returning it at the top of the tank. The UGF allows a bacteria bed to grow in the substrate. Underground aquarium filters are best for tanks under 40 gallons and are quite reasonably priced but do have limitations. Using a UGF, the waste tends to get sucked down into the gravel so your gravel MUST be vacuumed deep down; they also tend to clog and are not recommended if you want to have live plants. On the other hand these filters require little or no maintenance; never need a cartridge change and never wear out.

Power Filters

Power filters are the most commonly used aquarium filters for mechanical filtration in tanks under 55 gallons. Typically, they hang off the back of the tanks and provide mechanical filtration by pulling the water up into the unit and filtering through a cartridge. Most of them also have a carbon cartridge to provide chemical filtration and some even have a “biowheel” that provides biological filtration. Many aquarists use a power filter in conjunction with undergravel aquarium filters for increased water quality.

Canister Filters

Canister aquarium filters are typically used in larger tanks (55 gallons and up) and are recommended for saltwater tanks. They provide a complete solution for all types of filtration and are designed to be flexible so that you can decide how much of each type of filtration is needed. These filters usually are kept hidden in the base of the tanks stand and are therefore considered to be more aesthetically pleasing than the “hang on the back” kind of filter. They work by pushing the water through the filtration material and are considered to be a more powerful means of filtration than the power filter. It is a bit more complicated to set up, however and the maintenance is not as easy as a power filter.