Should An Aquarium Filter Be On All The Time?

You might have heard that it is not necessary to keep the heaters and lights on in your aquarium 24/7. This might have then got you to question whether you should keep your aquarium filter on at all times too. So, should your aquarium filter be on all the time?

An aquarium filter essentially cleans the tank water of toxic buildup of ammonia and nitrates, debris, and aerates the water so your fish can breathe. It is necessary for your aquarium to have a filtration system to ensure your fish remain healthy. Hence, it is not a good idea to turn off your aquarium filter for hours at a time.

Below, I have discussed the key role that your aquarium filter plays in maintaining the well-being of your fish. Additionally, I have also shared how long you should leave the aquarium filter on, what type of filters are available, how to choose the right filter, and more!

How Long Should Your Aquarium Filter Be On?

Aquarium filters are designed in such a way that even if you run them 24/7, they will continue to run smoothly. Hence, the same worries you might have about heaters and lights malfunctioning, resulting in your fish being harmed, does not apply to filters.

Moreover, it is extremely important for you to ensure that your filter is running at all times. This is true because your fish need oxygen to survive, and filters play a huge role in maintaining adequate oxygen levels in the tank.

Amongst other functions of a filter, as discussed below, making sure that the tank stays aerated is one of the major functions that directly affect your fishes’ mortality!

Can You Turn Off The Aquarium Filter At Night?

One of the most common reasons that fish tank keepers want to turn off their aquarium filters at night is because the filters are loud. They make a lot of noise, which disturbs your otherwise peaceful sleep.

However, turning off your aquarium filter at night, or any other time, for hours at a time is not a good solution. You will soon end up with a very dirty fish tank, sick or even dying fish, algae, toxic levels of ammonia and nitrates, and debris.

Hence, you can resolve this issue by searching for quiet filters instead. I have listed a few such options below.

Also Read: Can I Turn off the Aquarium Filter at Night?

What Is The Function Of An Aquarium Filter?

In order to understand the importance of having your aquarium filter on all the time, you need to understand what roles it plays in maintaining your tank. Hence, here I have listed all the major functions of an aquarium filter.

There are three methods of filtration: biological, mechanical, and chemical filtration methods. Your aquarium filters work to clean the tank water in one or more of these three methods.

Biological Filtration

In the biological filtration method, the bacteria in the tank break down the harmful chemical byproducts present in the aquarium into less toxic substances. This also shows that cleaning out your tank completely could do more harm than good, as you would lose a lot of the necessary bacteria that clean up your tank!

This will be more apparent by understanding the Nitrogen Cycle. This cycle occurs in every fish tank when some bacteria first break down the excretion of the fish, the uneaten food in the water, etc. to ammonia. Then, a different type of bacteria, called Nitrosomonas, breaks this ammonia down to less toxic nitrites.

Hence, for these bacteria to grow and survive in your tank, they will need a surface that is accommodating for them. And it is important to note that filters with biological media that are more exposed to the air have the greatest capacity to perform the filtration efficiently, as these surfaces are where the bacteria grow.

Mechanical Filtration

Mechanical filtration is the process that removes particulate matter in the water. This process occurs when water is forced through a filtration media that is designed to retain such particles.

There are many filters available in the market, which will help you ensure that there are no harmful particles floating around in your fish tank. And I have listed these different types of filters down below.

However, to ensure that mechanical filtration takes place in your fish tank, you will need to clean your filtration media regularly. This way you will be getting rid of the particles collected in the filtration media. This will also mean you are regularly restoring the media’s filtration capabilities.

Nonetheless, do take note that the media used should be one of the following: a type of foam, filter floss, micron paper pleats, pads, or diatomaceous earth.

Chemical Filtration

This third method of filtration is equally important in making sure your fish tank is clean.

Chemical filtration essentially removes the toxic chemicals present in the tank water. This process occurs when the water passes through a chemical media or resin. This chemical media or resin then retains the unwanted chemicals.

It is also important to note that by making the chemical filtration media a part of the filtration system of the aquarium, you will not have to perform water changes quite as frequently. However, this does not mean that you can completely avoid performing water changes. It simply means you will have to do it less frequently!

Also Read: How to Clean And Maintain Aquarium? – The Easiest Way

Different Types Of Aquarium Filters

Now that you know more about the functions of filters, let me tell you about the different types of aquarium filters. I have listed them below with some key information about each.

1. Internal Filters

As suggested by its name, internal filters live inside the aquarium itself. They either are usually mounted on the inner wall of the aquarium with the help of suction cups or are placed on the substrate.

Most internal filters have an airline that is attached to the filter on one end and an air pump on the other end. The air pump always sits outside the aquarium and pumps air into the filter, which then releases the air onto the surface of the water. This allows the air bubbles to create water movement, which ultimately allows the filter to perform filtration.

Thus, when the air is pumped into the filter, it also sucks up water at the bottom of the filter. This water then passes through a coarse sponge, which traps the debris.

It is important to note that internal filters usually perform all three of the filtrations mentioned above.

2. Power Filters

Power filter is the name given to those filters that hang on the back of the aquarium. I am sure you have laid eyes on this at some point, especially if you are an aquarium hobbyist. These filters perform all three types of filtrations and are easy to maintain too.

Power filters have a u-tube attached to them, through which water is pulled and passed through a filter media. Most power filters use cartridges that use activated carbon, which traps unwanted products. However, these cartridges tend to clog up very fast causing the filtration to be not as effective. So make sure to clean out these cartridges regularly (around once a week)!

3. Canister Filters

Canister filters are the best filters to perform mechanical filtration. This is due to the fact that they are pressurized units that have finer filter media placed inside. Hence, when water is forced through this media, the smaller particles that would not have been trapped by other filters are trapped.

This is also true for chemical filtration because the pressurized water passes through the fine material in the canister filter.

You will need to place the canister filter beneath the aquarium. This is ideal because the filters can then be filled up with the tank water simply by the force of gravity!

4. Under Gravel Filters

This filter consists of a plate that is under the substrate, which might consist of gravel or other substrate materials. This plate has tubes, called uplift tubes, attached to it. These tubes extend upwards towards the surface of the water.

Inside these uplift tubes are air stones, or a power head is installed on top of the tube to force the water through the tubes from the substrate.

Through this type of filter, all three types of filtrations take place.

5. Wet/dry Filters

Similar to canister filters, you will also need to place the wet/dry filters beneath the aquarium. But the wet/dry filters have an overflow device attached to them, which consists of two boxes. Each of these boxes is placed inside the aquarium and outside (beneath the aquarium).

A u-tube then transfers the water from the box inside the aquarium to the one outside. As the water flows into the outside box, the water passes through a pre-filter material that traps the bigger waste particles.

After this, the water passes to the main filter unit, where the water is cleaned before being fed back to the fish tank.

Also Read: Aquarium Filter Media Type and The Arrangement

Choosing The Right Filter For Your Aquarium

As mentioned above, there are three types of filtrations that occur by installing filtration systems. Each filtration is equally important as the other two. Hence, I would recommend that you install a filter that performs all three types of filtrations: biological, mechanical, and chemical. This especially applies if you have a freshwater fish tank.

However, do make note of whether your fish enjoy a lot of water movement or not. If not, then you should opt for a filter that does not cause a lot of water disturbances.

Another thing to keep in mind is the size of your fish tank. For example, if your tank can hold more than 30 gallons, you should opt for canister filters. However, if your tank is around 10-15 gallons, then opt for power filters or under gravel filters.

Finally, rest assured that most manufacturers of filters give a recommended tank size on the filter itself. Hence, if you have any doubts, you can always check the label on the filter to make sure!

Water Filters And Air Pumps: Which One Do You Need?

You now know the functions of a filter, and that they are an absolute necessity. But do you think you need an air pump too?

An air pump simply maintains water movement and surface agitation. This is required so that your fish do not starve of oxygen at any point.

An air pump is especially required if you are using external canister filters that play no role in causing any surface agitation. Air pumps can also help to force water through a filter, to make the filtration more effective.

However, if you are using a powerful filter that causes surface agitation and adequate water movement, then you do not need an air pump!

Also Read: How To Maintain The Oxygen Level In Aquarium?

Final Words

Remember that your aquarium filter is the one piece of equipment that is keeping your fish tank clean, your fish healthy, and the toxins level in the water under control. Therefore, installing a filtration system in your aquarium would be my number one recommendation.

Next, understanding which filter to purchase for your aquarium is also equally important. For instance, if your fish love calm waters but you have fitted your tank with a powerful filter that causes a lot of water movement, it could very well be a disaster! Hence, make sure to do your due diligence before purchasing a filter.

Hence, now that you know that your aquarium filter plays a major role in keeping your fish alive, you will think twice about turning it off before going to sleep!