What filter should I choose for my aquarium?

By Tharouet Maamouri for HAPPYARIUM.com

With such a variety of products available on the market, it is sometimes confusing to decide on the best filter to choose for your tropical or marine aquarium.

Most people end up using the filter which was provided with the fish tank itself. However convenient that is, the supplied filter is not always the best fit for your aquarium setup needs. Owners should be aware that having an inadequate filter can cause a negative long term impact on the running cost of your tropical or marine fish tank. Besides, inefficient filters will result in more frequent aquarium cleaning sessions and much more tempering with the aquatic ecosystem. Ultimately, this can lead to unnecessary stress to the fish population.

Before we get to the different types of filter available on offer, it is best to understand the basics of how a fish tank filter works. Regardless of its make or type, all aquarium filters are composed of two main parts, the water pump and the filtration medium.

The water pump is a simple device also called a power head, its role is to create water current and force the water within the aquarium through the filter medium.

The power of the water pump is expressed by how many liters of water it is able to pump per hour. For example, a water pump of 500L/h will push 500 liters of water through the filter medium every hour.

So what does this mean to you?

If you have a 100 liters aquarium, a filter with a power of 500L/h will filter the entire water content of your aquarium five times every hour.

How does it filter it?

The second section of every filter is the filtration medium. This section is made out of multiple layers used to trap fish and plants waste and neutralise harmful toxic materials. There are tow types of aquarium filter mediums, physical and chemical.
The physical filtration mediums are the like of sponges and ceramic rings. Those are porous materials that will trap large particles inside the filter. Mechanical mediums will need regular cleaning as part of your aquarium maintenance routine. Occasionally, they will need to be changed.
The chemical filtration mediums are the like of carbon pellets and nitrate sponges. Their primary function will be to help breaking down the toxins, produced as a result of fish waste, and convert them into less harmfull element.

It is important to mention that the filtration mediums and the water inside your aquarium will house the fish friendly bacteria that will thrive inside the sponges and create the aquarium cycle. The Bacteria will live in symbiosis with your tropical fish and help breaking down food waste and other impurities. This is referred to as the biological filtration medium. The aquarium cycle will be discussed more in depth in a separate topic.

Now that we know the basics! Which aquarium filter type should we choose?

There are 2 main types of filters, internal and external ones.

Internal aquarium filters

Internal aquarium filters can either be built-in the back of the fish tank or attached by the use of suction cups or clips on the inside of the tank. This type of filters is usually small and less powerful. Most importantly, they are visible inside the aquarium and use up space that is better left to be enjoyed by the fish. These are suitable for small aquariums of 60 liters or less. Happyarium Internal Filter

The external filters

The external filters are usually bigger, more powerful, and use more filtration medium. They are able to process larger quantities of water per hour and provide strong water circulation. External filters are suitable for all aquariums especially the larger tanks. They free the space inside the fish tank and make the aquarium in need of less maintenance and cleaning sessions.

Nevertheless, the main incentive behind having and external filter is the fact that cleaning or replacing the filtration mediums does not involve touching your main aquarium and therefore reduces the level of stress on the fish.

Other filters

Other types of external filters are available such asSump Tanks. Sump tanks are a very effective way to filter your aquarium water. They work in a similar way to any other type of filter; the only difference is that the process happens in an auxiliary tank situated underneath the aquarium itself. Sump tanks are suitable for the larger aquariums and, mostly, coral & marine setups. They are not for the novice and are prone to breakdown due to the more complex plumbing required for their functioning. The advantage of the sump tank is its ability to host a Protein Skimmer and more powerful water pumps. They also increase the contact surface of the water with air and improve oxygenation.

All type of filter can include Ultraviolet lamps that help burn and sterilise the water for a crystal clean finish.

Our recommendation is to choose an internal filter able to filter the entire contents of your aquarium at least five times per hour and passes through no less than three filtration mediums, a sponge, ceramic ring and a carbon medium. The addition of an ultraviolet lamp is also highly recommended.

Tips to remember:

Filters are an essential part of any aquarium setup (Marine or tropical).

The power of the filter should be adequate to the size of your fish tank.

Use the filter output nozzle as a way to direct the water in your aquarium .