Aquariums, Information

How Often to Change Aquarium Filter

Photo of author

by Jason Matthews


Last updated:

An aquarium is not just aesthetically pleasing but also has a calming effect on the room. With the hectic and fast-paced lives that people lead today, keeping and maintaining an aquarium can be relaxing and have a de-stressing effect.

When you keep fish, an aquarium filter is essential. It will not only aerate the water but also ensure that the environment is healthy for the fish. However, when you install a filter, you also need to know how often to clean and change it. Otherwise, it will make the water toxic and cause harm to the fish.

Related article: How to change aquarium filters without losing bacteria

How Often Should You Change Aquarium Filter

The filter makes your aquarium efficient and ensures that dirt, debris, and waste do not pollute the water. Besides regular cleaning, the filter also has to be changed periodically. That will ensure the filtration system in the aquarium works optimally and maintain the quality of the water.

Home aquarium with fishes, driftwood and greenery.

How often you should change the aquarium filter depends on the kind of filter you are using. Some filters can go for extended periods without requiring a change while other filters need to be changed more frequently. At the same time, it is essential to note that if you change your aquarium’s filter too often, it can get rid of beneficial bacteria, making the water unsuitable for your fish, especially if you have a freshwater aquarium.

Here are the different types of filters and how often you should change them:

Hanging Filters: These are the most ubiquitously used aquarium filters. If you have this filter, it should be changed once a week. Make sure when you replace the filter media, you also clean the filter.

AquaClear 50 Power Filter, Fish Tank Filter for 20- to 50-Gallon Aquariums
  • Aquarium filtration system that offers superior contact time with filter media and energy efficient pump lowers operating costs

Last update on 2022-09-24 / Affiliate links / Images from Amazon Product Advertising API

Under-gravel Filters: These filters are placed under the gravel and hence, they are out of sight. Make sure you vacuum the gravel every 2 weeks and clean the filter. Also, look to replace the filter once a month to ensure optimal filtration. Also, see our guide to cleaning aquarium sand and gravel.

Sponge Filters: In this type of filter, the water is pushed through the sponge and it traps dirt and debris. It also provides biological filtration. Usually, sponge filters need to be changed every week when you change the water in the aquarium.  

In-the-Tank Filters: These filters are very similar to hanging filters. So, just like the hanging filters, they too need to be replaced once a month. Between two replacements, make sure you clean the filter each week when you are changing the water in the aquarium.

Canister Filters: These are enclosed filters and you do not have to change or clean them that often. You can clean the filter every 3 to 4 months but at the same time, if the filter is beyond cleaning, make sure you replace it right away.

See also: Carbon aquarium filter – how long do they last?

The Bottom Line

It is advisable to fill a bucket with aquarium water to clean the filter. This water will not contain chlorine and other chemicals that are present in tap water. Use the cleaning to check the filter and if you find that it cannot be cleaned or it has an issue, replace it straight away.

As a rule of thumb, biological and mechanical filters need to be changed each time you change the water. On the other hand, chemical filters need to be changed when they are falling apart. However, make sure you change the filter media regularly to ensure your chemical filter does its work.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

Leave a Comment