The filter is your biggest ally when it comes to keeping your aquarium clean, leading to sparklingly clear water.
So what is a filter cartridge , the filter automates the process of keeping your water clean via mechanical, biological, and chemical filtration; however, the filter does need some attention from time to time.
In this post, we’ll talk about cartridge filter for fish tank; specifically, the question is – can you clean fish tank filter cartridge?
We’ll explore whether you can reuse aquarium filter cartridges and explain how to clean aquarium filter cartridge.
Let’s get started.
Benefits of Cartridge Filter for Fish Tank

Most of the hang-on-back and canister filters use filter cartridges that are meant to be replaced periodically.
This is intended to make things convenient for you; however, replacing cartridges may not be ideal for your fish tank, for reasons we’ll see later.
Like any filter, cartridge filters offer physical filtration by trapping debris and large particles, and biological filtration by housing a bio media that can be home to a colony of nitrifying bacteria.
One other distinct feature of cartridge filters is the chemical filtration it offers, setting it apart from basic filters like sponge filters.
This is usually in the form of activated carbon, which can remove odors, discoloration from tannins, leftover medicine, and other harmful chemicals.
Some even have advanced substances such as zeolite, and ion exchange resins.
So, the chemical filtration of cartridge filters, along with its other functions, keeps the aquarium water in tip-top shape.
Why Reuse Aquarium Filter Cartridges
Most manufacturers of cartridge filters would recommend that you discard the cartridge and replace it with a new one after a lapse of time.
This seems simple and straightforward, but there are a couple of good reasons why you should not follow this ‘official’ advice.
1. Cartridge Filter Cost
We all know that the hobby can lighten your wallet to some extent, but buying cartridge replacements periodically can really drain you financially.
Ideally, maintenance cost is something that you would like to keep down; it’s one thing to spend your cash on a big lavish aquarium, but spending money on a regular basis can cost you a lot in the long run.
Most sellers recommend that you change your filter cartridge every month; many aquarists believe that this is an unnecessarily short time span and is nothing more than a ploy by the manufacturers to make more money from cartridge sales.
2. Replacing Cartridge Removes the Beneficial Bacteria
As you may know, the filter media houses the nitrifying bacteria that convert ammonia into less harmful nitrates.
You should also know that it takes time for these bacteria to colonize the bio media, a process known as nitrogen cycling. It takes about 4-6 weeks to cycle an aquarium.
Taking away the filter cartridge housing the bio media also takes away a large chunk of these nitrifying bacteria – it may take a while for the bacteria population to reach its prior levels after that.
This could lead to an ammonia spike, which could end up being dangerous for your fish – in fact, some aquarium owners have reported that their pets died after a cartridge change.
You can see why removing the bio media in its entirety is such a bad practice.
Can You Clean Fish Tank Filter Cartridge

So, can you reuse fish tank filter cartridges?
Yes, you can, but you need to clean them periodically, as not replacing them means they will get dirty after a while.
You can indeed clean the filter cartridge, but some aspects of it, such as the activated carbon, will lose its effectiveness after a while and there’s no way to clean that.
The idea behind cleaning the cartridge is to get rid of the debris and large particles that impede the flow of water through the filter – a proper flow is important for the functioning of the filter. In the worst case, the bacteria can die from lack of oxygen and nutrients due to insufficient water flow.
That being said, you should only clean it if it’s too dirty and you notice the flow of water decreasing.
If the cartridge has been there for too long and is excessively dirty and heavily clogged with the flow of water not improving even after cleaning, it is probably time to finally get a new one.
So how often should I change my filter cartridge – you should be able to use a single cartridge for 6-12 months with regular cleaning – that’s miles better than the cartridge-a-month nonsense being pushed by the filter manufacturers.
Let’s look at how to clean a filter cartridge for a fish tank next.
How To Clean A Fish Tank Filter Cartridge
Cleaning the filter cartridge is pretty straightforward – after you turn off the filter and remove the cartridge, just rinse it in water.
But you shouldn’t use just any water; tap water contains chlorine and can kill your bacteria. Using soap also does the same, not to mention that soap is highly dangerous to fish as well.
Ideally, you should use water from the aquarium itself as it is the safest water for your bacteria with identical parameters – you can coincide the cleaning with your periodic water change to get the water you need in a bucket.
Gently rinse the filter cartridge in the water you collected – the idea is to get rid of the large particles that stop water flow, not to disturb the bacteria too much.
Rub the floss side of the cartridge with the palm of your hand, again gently.
You can clean the pre-filter more vigorously, as it contains no bacteria. Your reusable fish tank filter cartridge should have a pre-filter as it prevents the cartridge from becoming dirty too fast.
If your filter doesn’t have one, you can try making one yourself.
If your filter happens to have multiple cartridges, or you have multiple filters, wash one at a time to preserve some of the nitrifying bacteria.
Even if you have a single cartridge, you can try cleaning just half of it at a time.
Also, avoid scheduling other cleanings of your aquarium atthe same time you clean the filter; for example, avoid cleaning the substrate at the same time because some of the bacteria are found there as well.
Consider adding activated carbon separately as it loses effectiveness after a while; some cartridge filters have a separate component for chemical filtration, making life easy for you as you can just replace that while keeping the bio filter.
Conclusion
By now, you should know how to clean filter cartridge aquarium; as we have seen, it’s pretty straightforward.
But there are a few things you should keep in mind so that you don’t wipe your population of beneficial bacteria.
The main benefit to replacing the filter cartridges is the chemical filtration it provides, but aquarists have found other ways of getting it or just forgone the chemical filtration part, which isn’t that essential.
Reusing the filter cartridge not only saves money, but also makes sure your aquarium has uninterrupted biological filtration, which is vital.
Thanks for reading.