How Long Do Fish Filters Last?

One of the most important things you can do for your fish is to keep their environment clean. Just like the air that you breathe, your fish breathe in water and your filtration system is what keeps the breathing atmosphere clean for your fish. How often do the filters need changing?

• One of the many things to consider when asking how often do you change a filter is what type of filter are you talking about? Is it chemical, biological or mechanical? How large is the tank it is filtering? What types of fish are in the tank? As you can see, there are many items that must be looked at prior to answering the question.


• As a general rule large tanks need to be done with mechanical filtering methods. This is done with a power filter using pads or cartridges. These normally won’t need changing until they deteriorate and that normally occurs in about a month. Should the water become a bit cloudy you can always rinse them for some relief.


• Should you be using a sponge filter there is a short quick test to determine if it is in need of replacing. Take it out and squeeze it. If the sponge does not retain its original shape within seconds it most likely needs to be replaced. If the flow of the water in the tank is restricted or gets cloudy may indicate the need for changing as well.


• When using biological filtration it takes around five to six weeks for the helpful bacteria to reach positive proportions in the filter material. It should never be cleaned or changed prior to this happening. These bacteria will remove ammonia and nitrates from the water.


• One thing you will want to try to stay away from is purchasing filters that are not recognized within the industry. They may not be up to standard and may not last nearly as long as they should.