Types of Aquarium Fish Filter

One of the most important aspects when it comes to setting up home aquarium for your pet fish is selecting the right filter. Filter can be in different forms, some large, some small, others are made to cater for low volume of water, some have better filtration capability compared to the others and basically each has its own function and filtration method. Generally one of the most important parameters on how you classify a filter is based on:

1. The type and its filtration principle
2. The capacity measured by how much volume of water it can take per hour

Let us analyze the options that can determine your selection process

Undergravel filter
Undergravel filter works by using air as the driving force to push the aquarium water through a layer of gravel acting as the filter media which is placed on top of a sieve plate. In this context, the gravels function not only for decoration purpose but it is also playing the role acting as the media for the filtration process. One of the advantages of using this type of system is that there is a wide surface area for the filtration to take place and thus leads to increased efficiency. With the air pump acting as the driving force to create a vacuum condition below the plates, basically the whole area covered by the gravel effectively become the filter setup. Since there is a large surface area, this will allow growth of healthy population of bacteria and the whole principle is based on biological and physical aspects to remove the waste.

Layers of undergravel media including bio-balls provide excellent filtration process

However, one of the disadvantages is that once the media chokes up, it will take a lot of time for the cleanup process since it will involve moving out the fish and then digging up the layer of gravel to allow removal of scum choking and prevent water from flowing though. This type of filter is also not suitable to be used for large aquarium because it will create a messy work every time when it comes to maintenance work. Furthermore, with large aquarium, you will need to work out the calculations to size the air pump capacity accordingly or else the system will not function properly. Thus the limit and recommended aquarium size when using undergravel filter should not exceed 20 gallons.

Some of the ways to beautify and decorate the aquarium

Canister Filter

Example of Canister filter

Canister filter system is the most popular and commonly used in every fish setup. Instead of air pump, the working principle relies on pump to create the driving force to push the water across the filter media which can be made of different types of materials such as wool, carbon, bleaching earth, fine gravels. Depending on how the arrangement of the media is decided, basically it should at least cover on both biological and mechanical aspects to effectively clean the water. Canister filter is widely preferred because it offers better filtration capacity and depending on the selection of models, some offer a very effective dirt removal process to trap and produce crystal clear aquarium water. Usually common filter with the chamber that contains the media are placed outside externally. Since it uses pump to deliver the pressure, it can be placed at any location even at the bottom of the tank and then uses an inlet line placed inside the aquarium tank for suction and another to deliver the water back. Some models are capable to treat huge volume of water, supporting at least 100 gallons and beyond with a few particular models made exclusively for 500 gallons as well.

General maintenance of the system is very simple and depending on the manufacturers’ construction, it can be very easy to open and reassemble back. Although choking is a common problem with all filters but however, since the maintenance aspect has been made easier compared to the undergravel system, most pet owners prefer using this for their aquariums. One disadvantage is that since it uses materials that must be replenished like for example the carbon and bleaching earth, there is a certain cost attached to replace it back.

Sump system
Aquarium sump system filtration principle works just the same like the canister filter having filter media to take care of the filtration process but the difference is that since canister filter media is loaded into a closed bucket, the sump is made up of an open channel setup, usually another separate aquarium divided into several open compartments. The whole basic design is also very simple and easy to understand. What it requires is an overflow line from the aquarium located at an elevated height and a pump inside the sump to return the water back to the main display tank at the top. This will create a circulation system which allows the water to flow through the individual compartments filled with filter media so that treatment steps can take place here. Just like the canister filter, the media can comprise of different types of materials and the best setup should focus on biological process removal in order to get the best quality of filtered water. Usually bioballs can be filled into the compartment in order to provide wide surface area for the growth of bacteria and this applies in similar manner if you decide to set up a refugium for use in aquarium marine/saltwater systems.

One disadvantages of using this type of setup is that you will require a lot space to place the aquarium and usually this is located at the bottom of the main display tank enclosed inside a cabinet (with proper ventilation) in order to hide the unsightly appearance of pipes. Most conventional sump system is designed and custom-made by the owners but there are also complete systems sold by aquarium manufacturers. In order to create your own sump, make sure that you have an overflow line which can be done by drilling a hole for your main display tank so that that the water will flow out naturally by gravity going to the tank below. Never use a pump in place of the overflow line to deliver the water to the sump because by doing that, you will need a matching pump with the same capacity to return the water back again to the main tank. Furthermore, if you are using two pumps, chances of overflow happening is higher because if one of the pumps fail, the water will overflow out either taking place in your main tank or it could happen at your small sump. Thus, this will create a messy condition and potentially flood your own house. A well equipped sump system is enough to support the main display tank of any size. The main limiting factor is actually on your pump to deliver the flow circulation.

Conditions for breeding aquarium fish

Box filter
Box filter is perhaps the simplest of all in terms of construction and setup and one which require the lowest cost to purchase. The working principle is similar just like an undergravel filter because you will need an air pump to provide the driving force to draw the water into the box filter. But however since the box is so small, it can only provide a small volume of filtration capacity and most of the time, this is not enough to support even a 20 gallon tank. The most the box filter can accommodate is 5 maybe 10 gallon tanks but even then, it has to be constantly taken out to wash and clean the filter media. The filter media compartment is usually filled with wool and most of the time, depending on the amount of waste generation coming from your fish tank, the media will quickly get choked up usually in just a matter of 2 to 3 days. Placement of the box filter together with your fish also creates that unsightly appearance and also its presence also took up precious swimming space. I wouldn’t recommend anyone to use this type of filter unless they have a very small aquarium size with the fish that don’t generate huge amount of waste.