How Long Does a Fish Tank Filter Last?

How Long Does a Fish Tank Filter Last?

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A fish tank’s filter is one of the most important aspects of maintaining an aquascape. It helps remove debris, waste and toxins that would be detrimental to your fish if it were to stay there. But, when you’re looking to invest in a new filter, you may wonder how long does a fish tank filter last?

In general, a good filter for your tank should last anywhere from 7 to 10 years. But, this is going to be entirely dependent on the type of filter, how well you take care of it and brand reliability. While the actual device you use for filtration should last for some time, you will have to replace the media inside on a periodic basis.

How long does a fish tank filter last?

The filter that holds the media won’t require replacement until it stops working. The length of time this takes will vary between brands. Plus, the type of filter you have will also determine its expected lifespan. In most cases, however, you should only have to replace them when they cease functioning.

Of the three types, the media used inside the filter does require replacement from time to time. But this is also why many aquarists use more than one type of media in the same filtration system. It reduces frequent changing of the media and works together to boost the nitrogen cycle.

Also remember that, regardless of which one you use and have to change, you want to ensure you don’t disturb the nitrogen cycle too much. Severe shifts in tank chemistry can be disastrous to your fish. So, it may be a good idea to change out certain media in parts and then waiting a few days in between to replace the rest.


Biological filtration happens throughout the aquarium. The media intricately intertwines with the nitrogen cycle. This is where beneficial bacteria break down ammonia into nitrites followed by transformation into nitrates; providing a less toxic environment for fish.

Depending on the type of media and how porous it is, you shouldn’t have to change it for about two to four years. The only time you will have to find a replacement is if it falls apart. However, you should rinse it out in tank water once a month to reduce clogging.


The idea behind chemical filtration is that a porous substance or media absorbs particles, debris and cloudiness. This is excellent for when you have antibiotics for fish illnesses in the tank, which means it gets rid of things like copper, chlorine and other tap water impurities.

These absorbent chemicals bind and remove particulates from the water. Once saturated, it fills up and you have to replace it about once every other month. There are two general types of chemical filtration:

  • Activated Carbon: This has microscopic pores that attract materials to them. The fresher the carbon, the more effective it is. If you use some during medication, you should replace it when the dosage period ends. This will safeguard your fish against any problems.
  • Ion Exchange Resins: This type of media attracts specific molecules to adhere to them. Some attract nitrate or ammonia while others remove dissolved solids. When mixed with carbon, it strengthens the carbon’s potential while also helping to remove pollutants before it can enter the nitrogen cycle.


Out of all three types of filtration, mechanical will not affect the aquarium’s chemistry in the same way chemical or biological filtration does. Mechanical filters push water through something like a sponge and this removes solid debris. It keeps water clear and the tank clean.

This shouldn’t require a replacement unless it stops working, which should be around 10 years. Of course, if the media is falling apart, you’ll have to replace it. Other than that, you should only have to rinse it out with tank water every month. This is so you can keep clogging to a minimum.

Understand, though, any replacement of a mechanical filter (see Amazon) may cause problems with the chemistry of your tank. While the mechanical filter’s media is inert, it does build up the beneficial bacteria necessary for the nitrogen cycle. This means you’ll have to be careful when you do have to replace it so you don’t cause stress to your fish.

Final Thoughts

A fish tank filter can last for quite some time but the media you use is what will need periodic replacement. Higher quality devices will last about 10 years, so brand reliability will be a crucial factor. Of course, this will depend on the type of filtration you’re using.

Both biological and chemical filtration systems will have to have the media changed. You should only have to change out mechanical if the media falls apart or the machine stops working.

See Also:
Can You Clean the Fish Tank Filter Cartridge?
Why is My Fish Tank Filter Not Bubbling?
How Long Do You Leave the Filter on in a Fish Tank?
Can a Fish Tank Cause Allergies? (Explained)