Choosing the right filter for your aquarium can be hard sometimes. Because, you have to check several factors before finalizing one. And at the same time, you should have enough knowledge on what type of filter best suites for your aquarium.
Aquarium filter is the first priority after you buy a new aquarium for fish keeping. Because, filter is what maintain the clarity of the aquarium water. While maintaining the water clarity, filter makes flow in the water and through that, it reduces the chances of algae growth. And most of the filters are good place of bacteria colonization.
How to Calculate Flow Rate of my Aquarium Filter
The flow rate of the filter should be five times greater than the total volume of aquarium water.
For example, consider that your aquarium has 54 litres of water in it. Then, flow rate required for the aquarium filter is = 54 * 5 = 270 Litres per hour. 270 litres/hour means, 270 litres of water will go through the filter in an hour. This is as equal as filtering the water in your aquarium five times an hour.
How to check the total volume of water in your Aquarium
To find the total volume of the aquarium water, measure the length, breadth and height of the aquarium in centimeter. Multiply those measures and then divide the value by 1000. The result will be the water volume of your aquarium.
Total volume of aquarium water = length * breadth * height (in centimeter) / 1000
Please note that, here you have to consider height as the measure upto where water is filled.
Difference between pH, gH and kH
How to choose the right Filter for your Aquarium
Filter is chosen mainly according to the fish tank water volume and its interior.
The interior of freshwater aquascape has been divided into two: planted aquascape and non planted aquascape.
Best Filter for Aquarium with Water Volume 25 Ltr to 60 Ltr
If the water volume of a planted aquarium is between 25 to 60 litres, then one hang on filter is sufficient.
And, if it’s a non planted aquarium, then one sponge filter is sufficient for it.
Best Filter for Aquarium with Water Volume 60 Ltr to 600 Ltr
If the water volume is between 60 litres to 600 litres, then its best to choose a Canister filter. And, if its a non planted aquarium, then one UG Filter (Under Gravel Filter) is sufficient.
Best Filter for Aquarium with Water Volume above 600 Litre
If your fish tank/aquarium is of more than 600 litres of water, then the best aquarium filter you can use is Sump Filter (for both planted and non planted aquarium).
Difference between Hang On Filter, Canister Filter and Sump Filter
We have already discussed about different filters suitable for planted aquariums like hang on filter, sump filter and canister filter. Now let us check out the difference between them, i.e., Hang On Filter vs Canister Filter vs Sump Filter.
Hang On FIlter

The first main difference is their size. Hang On filter is very small, canister is of medium size and sump is the bigger filtration system among these. That why we have made these into different categories in the above section.
Hang On filter due to its small size, uses sponge media to filter the water. But you can also see the presence of activated carbon in some of them.
How does a Hang On filter works?
When the water passes through a Hang On filter, the waste particles get stuck on the sponges and thus the water gets clearer.
How to improve the efficiency of a Hang On filter?
To improve the efficiency of a Hang On filter, it is recommended to take out and clean the filter sponge once every 20 days.
Canister Filter

Canister filter is a medium category filter. It has a little more inner space than Hang On filters.
Here, apart from filter sponges, we can also add other filter medias like ceramic rings. Also, don’t forget to add a small amount of bacteria culture along with the filter media. You only need to wash a Canister filter once in every eight months.
Sump Filter
The main difference between a Sump filter and a Canister filter is their service period. While you need to service a Canister filter once in nearly every eight months, you only need to to service a Sump filter once every three years.
Biological Filter
By connecting air supply to the filter sponge, you can turn it into a Biological filter. It makes sure that there is oxygen supply in the water along with water filtration.
Sponge Filter vs UG Filter
It is recommended to clean a Sponge filter once every 20 days. Also, 30% of water should be changed weekly for the best performance.
In a UG filter, you don’t have to change water every week if you have already added bacteria culture to the bottom of the fish tank. If you haven’t done so, then it is recommended to change water every six months.
Top Filter vs Hang On Filter
Top filter is mostly used for small planted fish tanks. But, the Hang On filter is better than Top filter for this purpose as Hang On filter do not consume as much inner space of the aquarium as the power head of the Top filter does. If you have already installed a Top filter, then you don’t have to change it.
FAQs
Biological filter is one of the most suitable aquarium filter for breeders because, it prevent fries from getting into the filter. Some filters when kept in a fry tank, there is possibility that the fries get into the filter and die.
The structure of a pond is totally different from that of an aquarium, whether it’s an indoor pond or an outdoor pond. So, its better not to use the filtration setup of an aquarium in a pond. Also, filtration unit for a fish pond is more complicated than an aquarium.
Sump filter is the aquarium filter that require least maintenance. It is almost maintenance free, but it’s little expensive than other filters.