Does A Fish Tank Filter Always Need To Be On?

It is not big news when you consider how very fragile fish can be. Of all the pet choices you could make, fishes are one of the most difficult you could ever pick. Very delicate creatures. So, if you own a fish and you’re bent on keeping it alive, you have your work cut out for you.

So does a fish tank filter always need to be on? This is a question I’ve have gotten a number of times from fish owners and the answer is yes. It is never a good idea to turn off your fish tank filter. Shutting it down, even for just an hour each day can lead to problems as the filter plays a key role in your tank’s health. It protects your fishes from harmful materials.

Why Do You Need A Fish Tank Filter?

Fish tank filters are built to remove debris such as uneaten and decaying food, fish waste and dead plant matter from your water. It is really vital getting the junk out of the water, but this is only one of the important duties performed by your filter.

In the nitrogen cycle, colonies of good bacteria which live in your tank, convert toxic chemicals in the water to safe chemicals which your fishes can live in without dying. How does your filter play its part in this process? It does so by performing two functions;

  • It is one of the main places in your tank where the good microbe colonies do well and multiply, it also helps to aerate the water.
  • This second function is very vital as oxygen is needed in your tank, not only for the fish but also for the good microbes in it as in its absence, both your fishes and the microbes will die.

An air pump is often installed by new aquarium keepers to create bubbles in their tanks, believing it will add oxygen to the water. It usually doesn’t hurt and will actually add a little oxygen to the water but a good filter will circulate the water enough to provide all the oxygen with your fish needs.

By turning off your filter you deprive the microbes that live in there the oxygen essential for their survival since the water is no longer flowing over the elements inside.



Does A Fish Tank Filter Always Need To Be On for Fish to Survive?

The microbes in your tank are pretty hardy like your fish, so it isn’t going to hurt them much turning off the filter for a short time. But doing so regularly will ultimately lead to a deprivation of the good microbes the oxygen they need for survival and this could, if not checked lead to their death.

What happens when you turn the filter back on is one of the reasons why it should not be turned off in the first place. Some filters will regurgitate dirty water and debris back into your tank depending on how recently you cleaned them when you switch them off and then on. This means that always switching your fish tank filter on and off is a bad idea. You are basically dumping all the dirt you removed from the tank right back into it.

So, I will advise that if you want to do this frequently, try to clean your tank regularly.

Does A Fish Tank Filter Always Need To Be On?, Aquarium Fish Tanks UK

You may ask “will my fishes die if I turn off the filter“? ‘Probably’ is the answer. Chances are your fish will not die if you turn off your aquarium filter for one night. If you do switch off your filter for a very long time, then the chances are high that your fish will definitely die, even if they were initially very healthy.

Also, turning off you filter for a short time will not kill the good microbes in the water, as the reserved oxygen in the water will keep them thriving for up to a week maybe even more. However, making it a habit to frequently shut off your filter is not good as you are putting both your fish and microbe colonies in a bad situation.

Removing the waste from your tank is not all that filters do, as they also provide important aeration for your tank. You are only allowed to remove your filter once in a while, like when you want to clean it.

What Tank Filters Do And Why You Must Get One

If want to own a fish tank either for beauty or for business and you are considering if you should get a tank filter, don’t think too much, ‘you need one’. Getting one is as important as getting a tank.

What a filter does in a fish tank is that it cleans the water debris, prevents the accumulation of ammonia and nitrates (which is dangerous) and also aerates the water so your fish and useful microbes can breathe. So, if you wish for all or at least most of your fishes to survive then getting a filter should be your priority after getting a tank.

I know you may say “I could simply remove the fish, clean the tank, replace the water, then return the fish, so I don’t need a filter“. But I will tell you with a filter, you don’t have to stress yourself with regular clean-ups. It does the job for you and constantly changing the habitat of the fishes can be traumatising for them and sometimes, you may even injure the fishes or kill them in the process.

Also for saltwater fishes that require their saltwater, to be kept at an exact temperature, cleaning the tank yourself is no a good option, hence the need for filters as they make your life easier and reduces your chances of unintentionally killing your fishes.

But you should know, having a filter does not mean you can sit back, relax, and leave the filter to do all the work. You still have to monitor and maintain the filter by making sure it doesn’t get blocked and so lose its function. A lot of filters are available in the market today.

External, internal, chemical, mechanical, and even biological filters (where you grow cool colonies of good bacteria that help clean the water) are all available, so make sure you purchase the one right for your fishes.

In conclusion, your filter has to be on all the time even though your fishes most likely won’t die with it shut off for a short time. But continuously switching the filter on and off will negatively affect the health of the fishes and the useful microbial community in your tank. It could even lead to their death.