How to choose the right aquarium filter?

If you want your aquarium to look like something you and others will enjoy, you have to supply it with the right filter. This is important because the filtration helps with aquarium maintenance. Filtration consists of several types of filter media (filter materials).

  1. Mechanical filter media are used to collect solid particles (larger debris) from the aquarium.
  2. Biological filter media are essential for the optimal natural balance, as well as, nitrates and nitrites level in the water.
  3. Chemical filter media are mainly used for water with a lower quality of chemical composition. Activated carbon and zeolite are usually used because of their effect on the chemical composition of water.

Activated carbon or zeolite are usually used in tanks that are using low-quality tap water. This way, the activated carbon removes chlorine and any other harmful element which can be found in the water inside the tank. Aquarium owners that have chemical filter media apart from mechanical and biological ones must know that the activated carbon needs to be taken out after 6 months at the latest. After that period the filter media can release everything that was absorbed back into the tank.

aquarium filters

Biological filter media for the aquarium

If a higher quality water is used, it’s sufficient to use a filter with only mechanical and biological filter media. These filters are most commonly used today. Biological filter media can be found in almost every shop. That includes bio sponges, ceramic rings, bio-balls…

Bio sponge is incredibly porous. It is made from a plastic mass that is really favorable for the formation of beneficial bacteria. Ceramic rings are microporous and even more favorable for beneficial bacteria. Bio-balls are the most popular media among aquarists. They are usually round, the size of a ping-pong or smaller, and of different structures.

Unlike activated carbon, biological media is not thrown out after 6 months. Namely, biological filters are easily cleaned by a light rinsing in the aquarium water. This is done during the regular change of one-third of the aquarium water, once in two weeks or one month depending on the size of the tank and the capacity of the filter material. The best way is to fill a plastic bin with aquarium water and rinse the biological filter in it. After that, the filter material is placed back into the filter. In case that the biological filter is washed with chlorinated tap water, beneficial bacteria can be removed because of the chlorine and temperature difference. In that case, the process of forming beneficial bacteria has to be repeated. It is important to establish a normal water flow for this mass.

Aquarium (Perlon) wool which absorbs the mechanical debris found in the filter is most commonly used for mechanical filtration.

Internal aquarium filters

Aquarium filters can be divided into internal and external.

An internal filter can have a power head. Beneath them, there is a container in which the filter material is placed. They are not very popular among aquarists because they spoil the look of the aquarium. However, there is a solution for that. There are aquarium wallpapers manufactured by Aquadecor that can hide the filters.

The second group of internal filters are made by partitioning the tank with glass. One part is separated with glass, which is also usually hidden by wallpapers. If there isn’t any wallpaper, the filter looks really unflattering. The mass which is placed inside the filter is much or less the same, which means that both mechanical and biological media and even chemical media can be placed there.

External aquarium filters

Filter canisters fall into the category of external aquarium filters. They are extremely popular because they can be controlled. These filters can be placed anywhere outside the aquarium, except above it in case the filter turns off or stops working. Then the water that is inside the filter can leak into the aquarium. However, that can be solved by placing a check valve. These filters are really strong and have a higher water flow rate. Better quality filter canisters are cleaned once every 6 months or once a year depending on the amount of fish in the tank, type of fish food, etc.

Although canister filtration is the most expensive way of filtration, it pays off. The problem is that these filters can’t be used for aquariums with a capacity of over 528 gallons of water. In these cases, one filter is not enough for bigger aquariums, you have to use more.

Sump filters are also very popular among aquarists. They are placed beneath the aquarium. Their functioning system is more complicated and it’s usually used in sea aquaristics.

aquarium filters

Speaking of aquarium filters, we should mention that there are glass filters that are placed beneath the aquarium. This type of filter is rarely used today. They are connected to the aquarium with a system of communicating vessels with different types of pipes. They are not reliable because they can cause an overflow of the tank or the filter when the filter mass gets really dirty. That is the reason why filter canisters that are hermetically sealed or the ones inside the tank are more popular. There can’t be any overflow.