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How to Clean Fish Tank Filter Like an Expert – by Type

how to clean fish tank filter
Written by Immanuel Baranov
Last Update: March 8, 2022

A fish tank filter, although a cleaning mechanism of its own, also of course needs cleaning in order to continue to function correctly and do its job efficiently. There are many kinds of filters we use in our aquariums and it can be quite important to understand the specific cleaning methods related to the type of filter one uses so as to avoid potentially doing more damage than good below is a list of all the major filter types and there individual step by step cleaning guides.

Why Should You Clean Your Fish Tank?

Your fish tank is much like your own house. Over a period of time, dirt and grime and different kinds of mess accumulate and it becomes necessary to clean up. Fish are notoriously delicate creatures that respond negatively to even slightly negative or adverse changes to their environment. This makes imperative to keep their space clean, balanced, and nutrient rich, and impacts cleaning aquarium filter systems.

How Often Should You Clean Your Fish Tank?

As mentioned earlier, fish are very delicate, so cleaning a tank too often and disrupting the fish frequently can have a negative impact on their health. To be safe and make sure this doesn’t happen whilst still ensuring that the aquarium remains in a relative state of cleanliness, it is advisable to clean the aquarium about once a week. More often than this will disrupt the fish and less frequently will allow dirt to build up, nutrients in the water to run low, and other serious problems. The frequency of cleaning can also vary depending on the number of fish you have and the size of the aquarium.

How to Clean Fish Tank Filter

Cleaning Mechanical Filters

  • Take out a few cups of the water that exists in your tank to use in the cleaning process. This will ensure the fish are only exposed to the chemical balance they have already adjusted to.
  • Unplug your filter and take it off its mount
  • Pop it in a basin or bucket and use some of the water you took from the tank to wash the pad thoroughly.
  • Scrub the casing, filter pipes, and filter tubes. Ensure you get all the dirt off
  • Pop the pad back in and give everything a rinse off.
  • Now replace the filter where it was and plug it back in.

Cleaning Chemical Filters

  • Remove some fish tank water to use while cleaning
  • Unplug and remove the filter from its position
  • Remove the carbon from the filter and scrub the filter down
  • Replace the carbon with new carbon
  • Put the fish tank filter back and plug it in again

It is very important that you change and renew the carbon in chemical filters quite frequently. To know when you should, simply check if the water seems murky. If so, it is time for a carbon renewal.

Cleaning Biological Filters

Biological filters work by using necessary bacteria. This means scrubbing and seriously cleaning the filter would be counter-productive as you’d just kill off the bacterial colonies that are doing your filtering for you. You can remove the filter and rinse it off with some tank water but that is about as much cleaning as it requires, making it the easiest aquarium filter pump to clean.

Cleaning a Sponge Filter

This is much like cleaning a mechanical filter. Follow the same steps as mentioned under that heading. Ensure that you return the aquarium filter sponge and filter to the tank as quickly as possible so that the necessary bacterial colonies that have formed naturally do not die off.

Cleaning a Canister Filter

Canister filters do not require frequent cleans the way many other filters do. You can potentially go a few months between each deep clean. When you decide it is time for a proper clean, do as follows.

  • Detach the intake and outlet hoses, and make sure everything is unplugged.
  • Then take some water from the tank and put it in a bucket and transfer the filter media to this bucket for safe keeping.
  • Take your canister filter to the sink and empty out excess water.
  • Use another bucket with some water from your tank to rinse it out. You may also want to scrub down the hoses.
  • Be sure only to use water from your tank and absolutely do not use any chemicals as they will leave a residue that could really harm your fish.
  • Once everything has been wiped and scrubbed, reassemble it all, replace the filter media, and reattach the hoses.
  • Now you can plug it back in and rest assured you will not need to do that again for two or three months.

Cleaning a Hang-On-Back Filter

  • Remove some tank water and set it aside to be used for cleaning
  • Remove the filter and disassemble it
  • Scrub down each individual part thoroughly
  • Leave any sponge pad or bio-wheel in the tank during this process.
  • Reassemble the filter and replace the sponge, pad, or bio-wheel
  • Plug the filter back in as it was

Cleaning an Undergravel Filter

This is an internal filter and cleaning is best done at the same time as your water change as it requires getting under the gravel and thorough cleaning. The best way to clean and maintain this filter is actually to focus on vacuuming the gravel itself during water change.

  • In the midst of a water change, vacuum the gravel properly and move it around to loosen any stiff debris.
  • Take the filter out and rinse it in the tank water. Feel free to scrub it lightly. Heavy scrubbing is unlikely to be needed as most of the waist would have been caught in the gravel.
  • Replace the filter and the clean gravel
  • Continue with water change process

Regular Maintenance

It is advisable that you maintain a clean filter as far as possible but be sure not to clean it too often or so thoroughly that you wipe out bacterial colonies that your fish actually benefit from. If your filter has a component such as carbon or an ion-exchange system, be sure to replace the needed chemicals or parts as frequently as indicated by the manufacturer. This is the first step in understanding how to clean an aquarium filter with regards to these filter types. If you remember to and make a habit of cleaning your filter whenever you change the tank water you should maintain a good clean filter that will serve well.

Finally, as you can see, cleaning a filter, regardless of the type, is fairly straightforward. That said, it does remain an imperative part of maintaining a healthy and conducive aquarium.

About the author

Immanuel Baranov

My life is pretty much defined by my avid outdoor activities. I’m generally obsessed with fishing, skiing and occasional hunting and whitewater paddling. I’ve been active since my early years. I inherited my passion for fishing from my father who made frequent family trips to the banks of Sacramento River. Growing up, I did a lot of fishing in the vicinity. Now that I have two sons, our weekends are full of fishing activities. I would say, you need good spots where you can go out a lot for the thing you love. I had the privilege to grow up near numerous water bodies and I’m proud to say that I made good use of them. It’s also great to do something with kids that helps them learn patience, endurance and preciseness.

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