How to Determine Filter Size for Aquarium

How to Determine Filter Size for Aquarium?

It is imperative to determine the size of the filter for your aquarium. The rule of thumb is that the filter should be of enough size to pass your whole aquarium water four times from it in each one hour.

How to Determine Filter Size for Aquarium? You can feasibly determine the size of your aquarium filter by measuring how much GPH your aquarium needs from the filter. After that, measure, estimate, or calculate the required filter size for your aquarium. 

Proper filter size is the basis of so many things inside your aquarium, for example, cleanliness or water quality, gallons per hour flow rate, and so many other things like this.

How to Determine Filter Size for Aquarium?

Here, we will share a step-by-step guide to determine the filter size of your aquarium. Astonishingly, so many people are showing concern about this topic.

By viewing such a large number of requesting emails for this topic, we finally decided to write a blog on this. is going to make things easier for you people.

Just read and follow the guidelines, here we go. Let me share an aquarium filter size chart with you first;

Pump size Slow create DE filter Cartridge filter
¾ HP 40 24 100
1.0 HP 50 36 150 – 200
1.5 HP 65 48 300
2.0 HP 87 60 400
2.5 HP 105 72 500
3.0 HP 120 84 600

Measure GPH Water Flow Rate

First of all, take the pump out of your aquarium. You might be thinking that what is the purpose of the pump while we are going to determine the size of the filter.

But yes, there is an excellent connection between the aquarium pump and filter. Because the filter efficiency also depends upon the pump working speed.

Any size of the filter depends upon the efficiency of the pump. So take out your pump in another temporary tank or some container.

Turn the pump ON and calculate the GPH water flow rate. Learn from here how to do it. You have to measure the value at which it pumps the water with the help of a stopwatch. 

Check out Your filter Efficiency 

Now, when you are done measuring the GPH, then you have to check out your filter efficiency. Take out your filter from the aquarium for half an hour.

Now it’s time to adjust the filter in a temporary container and check how many times the filter is filtering the water.

Its filtration rate depends upon the efficacy of the pump. If the pump is doing its best, the filter will also clean the water fast.

But if the pump’s GPH rate is meager, then your filter device will not be able to filter the water properly.

Now, put the filter and pump back into their place inside your aquarium and turn them on.

Decide to Buy a New Filter

If your pump is working well, but the filter is not able to clean the water by completing its cycles, then you need to have a big filter in your tank.

If your fish tank is large, then you have to buy a big filter and vice versa for a small fish tank.

Another solution is that you can buy two medium sizes of filters for your big aquarium. But the thing is that they should work well.

Either the filter is big or small, it should work at its peak efficiency. It should complete four cycles in a big tank in about one hour.

But in a small tank filter should cover 5 or 6 cycles because the cause the water quantity is low. Similarly, A 30 gallon of tank requires a 130-140 GPH flow rate.

If your first working pump has a 150 GPH, then you should go for a suitable medium or large size for the filter. Many people add two filters in one fish tank.

What Are the Filter Sizes for Different Types of Aquarium?

There are so many different types of aquariums, all of you have in your homes. So we will share about different sizes of filters for these aquariums.

Filter Size for Freshwater Tank 

The standard or freshwater aquarium also needs a sound filtration system. If your freshwater aquarium is large, then you will need a large filter for a reasonable flow rate and filtration system.

If your tank is of standard medium size, then buy an average size of the filter. If the aquarium is small, then you will need a low filter.

There is no need to install a large filter in a small tank. Just buy a product according to your requirement and nothing else than this.

Filter size for Reef Tank

Reef tanks are the one which needs the highest flow rate of water in them. This tank is like a marine representing a lot of corals and big rocks along with the marine fish.

Saltwater fish cannot tolerate the poor water conditions and need a large filter in their aquarium. This tank filtration system should be excellent.

Otherwise, the fish is not able to survive in adverse conditions. You will also need a pump with a high flow rate to add a filter too.

A powerful filter is the primary demand of this aquarium. The big rocks and corals need nutrition from the moving water.

If your filter is too slow to work, then the water will not move properly, and the corals will not be able to get their food. So if you have a big reef aquarium in your home, you will need a large filter or two medium-sized filters for a proper filtration system.

Filter Size for Planted Tank 

Let me tell you that you need a small filter in your planted tank. If your aquarium has only plants in it, then they will require a high amount of carbon dioxide for their breathing.

They also need to do multiple biological processes, and there is no such need for a large filter for avoiding the hindrance in biochemical processes.

A small filter will have a low flow rate, which is suitable for a planted aquarium as there will be less turbulence for plants to get disrupted in their processes.

Which Filter Size do I Need for my Aquarium?

If your aquarium is significant, then definitely it will need a high flow rater in it and a big filter to clean the water thoroughly.

The filter size depends significantly upon the aquarium size. Yet you can also install two different types of filters in your fish tank.

The other thing you can do is to use two of the same filters in your fish tank, and they should be of a standard size if the tank is vast, their size will be more if the tank is extra-large.

If your tank is small, then you will need a low filter; the main thing is that it should be efficient. Either your filter is big or small, it should filter water and at a medium speed.

You can check out that if your pump is all excellent, still the cleaning is not proper, then you will need to change your aquarium filter.

Every filter should have a powerful filtration mechanism in any tank. It will help you to get the healthy, clean water of your aquarium.

The filter media should be significant to clean the entire aquarium water. Filter quality should be high to achieve the best filtration rate.

Read this article thoroughly, and you will be able to determine the size of your aquarium filter easily.

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