How to Clean Filter in Fish Tank

Cleaning the aquarium filter is a necessary and fairly simple procedure. It usually takes no more than 5 minutes of time.

The filter in the aquarium is the most important part of the equipment, a life support system for your fish, removing toxic waste, chemicals, and if it works properly, it saturates the water in the aquarium with oxygen. For a filter to work properly, you need beneficial bacteria to breed inside it, and improper care kills them, resulting in balance problems. Unfortunately, most filters lack simple and clear instructions so that the user can understand them.

Types of filtration


The simplest method in which water is passed through filtering material and cleaned of suspended solids, coarse particles, feed residues and dead plants. Both external and internal filters usually use porous sponges.

These sponges should be rinsed regularly to get rid of clogged particles. If this is not done, the power of the water flow decreases significantly and the quality of the filtration decreases. The sponges are a consumable item and must be replaced periodically.


An important species if you want to keep complex fish and have a healthy, beautiful aquarium. Simply put, it can be described as follows: the fish create waste, plus the remains of food fall to the bottom and begin to rot. This releases ammonia and nitrates into the water, which are detrimental to the fish.

Since the aquarium is an isolated environment, there is a gradual accumulation and poisoning. Biological filtration, also helps reduce the amount of harmful substances by decomposing them into harmless components. This is done by special bacteria that independently inhabit the filter.


This type of filtration used in emergency situations in the aquarium: poisoning, after treatment of fish, to remove harmful substances from the water. The water passes through activated carbon, whose pores are so small that they retain substances.

After use, such charcoal must be disposed of. Do not forget that you can not use chemical filtration during treatment of fish and it is not necessary if your aquarium is fine.

See also: Choosing Right Air Pump for Your Fish Tank

Clean the filter right!

Just washing the filter may not be the best idea, as doing so may destroy the colony of beneficial bacteria in it. Therefore it is important not to wash the filter when you make any global changes in the aquarium – a large water change, change the type of food or frequency of feeding of fish, or the launch of new fish.

At such times it is very important that the balance is stable, and the filter is a big part of a stable balance in the aquarium.

Cleaning the biological filter

Sponges are most often thought of as a mechanical filter that traps dirt from the water. Your fish, however, do not care how crystal clear the water is, in nature they live in far from ideal conditions. But it is important for them to be in the water would be as little decomposition products, such as ammonia.

And for the decomposition of ammonia and other harmful substances, are responsible bacteria that live on the surface of the sponge in your filter. And it’s very important to wash your filter in a way that doesn’t destroy most of those bacteria.

Sudden changes in temperature, pH, chlorinated tap water, it all kills the bacteria. To wash the washcloth in the filter, use water from the aquarium just rinse it in that water until it is more or less clean.

Striving for sterility in this case is detrimental. You can also do the same with the solids – karmic or plastic balls.

Good to know: Aquarium’s Size vs. Aquarium’s Weight

Changing filters

Many aquarists, change sponges in the filter too often, as advised in the instructions. Filter sponges only need to be changed if they have lost their filtering capacity or started to lose their forum. And it happens not earlier than a year and a half.

It is also important to change no more than half at a time. For example, in the internal filter sponges are made up of several parts and only one can be replaced at a time.

If you replace only a part, the bacteria from the old surfaces will quickly repopulate the new ones and there will be no imbalance. By taking a break of a couple of weeks you can completely replace the old content with the new without damaging the aquarium.

See also: Benefits of Live Plants in Fish Tank

Impeller care

All aquarium filters contain an impeller. The impeller is a cylindrical magnet with an impeller that serves to create a current of water, and is attached to a metal or ceramic pin. Over time, algae, bacteria and other debris accumulate on the impeller and make it difficult to operate.

Cleaning the impeller is very simple – remove it from the pin, rinse under a pressure of water, and wipe the pin itself with a rag. The most common mistake is simply forgetting to do this. And contamination significantly reduces the life of the impeller and the most common cause of filter failures is contamination of the impeller.

Develop your own aquarium filter maintenance schedule, write down the last time you did it, and regularly check ammonia, nitrite and nitrate levels in your water.

See also: Filtration Media – How Does It Work


Can I Just Wash My Fish Tank Filter?
The short answer is no. While it may be tempting to just give the filter a quick rinse, this can actually damage the filter and reduce its effectiveness. Instead, you should use a filter cleaning solution specifically designed for aquariums. This will help remove any build-up of debris and bacteria without damaging the filter.

Can Fish Tank Filters Be Cleaned and Reused?
Yes, fish tank filters can be cleaned and reused. However, it’s important to note that the filter should be replaced every few months. This is because the filter material can become clogged with debris, reducing its effectiveness.

How Often Should I Clean Filters in My Fish Tank?
It’s recommended that you clean your fish tank filter every two to four weeks. This will help keep the filter in good condition and ensure that your tank remains clean and healthy.

How Do You Clean an Aquarium Filter Without Losing Bacteria?
When cleaning your aquarium filter, it’s important to take steps to ensure that beneficial bacteria are not lost. To do this, you should use a filter cleaning solution specifically designed for aquariums. This will help remove any build-up of debris and bacteria without damaging the filter. Additionally, you should avoid using hot water, as this can kill beneficial bacteria.

Reyus Mammadli/ author of the article

I have had pets since childhood: cats, guinea pigs, rabbits, geese, chickens, ducks, parrots, aquarium fish and dogs (in the yard). Of course, I constantly encountered diseases of pets and treated them. Glad to be able to share my skills and experience, as well as advice on caring for and adapting these critters and birds.

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