How does a sponge filter work instructions on how to use and maintainSponge filter use permeable material and frictional force to trap particles in the liquid. They come in different sizes and offer biological and mechanical filtration in a tank. Even though they are brilliant devices, they may not necessarily be aesthetical-pleasing.

Keep reading to learn about how the sponge filter works and how to clean them in your home.

How Does a Sponge Filter Work

Here’s how a sponge filter works:

  • The sponge filter traps dirt in the tank
  • Clean water flows into the filter causing bubbles
  • Improves oxygen solubility while cleaning the tank water

– Sponge Filter Traps Dirt in the Tank

The sponge filter catches the debris using frictional force thereby allowing only clean water to flow back into the tank.

– Clean Water Flows Into the Filter Causing Bubbles

You see, the air produced by the air pump travels through the tube into the filter. Then, it fills the hollow middle cavity of the sponge until it causes tiny bubbles to form.

– Improves Oxygen Solubility While Cleaning the Tank Water

These bubbles increase the oxygen solubility and also assist the sponge in sucking water through the tube and out of the filter. As the sponge drags the fluid into its porous surface, it catches debris. So, the water that flows through the filter comes out clean.

How to Setup Your Sponge Filter

It is very easy to use a sponge filter setup in your aquarium but you need to set it up first. To do this, you should learn about its components and how to assemble a new sponge filter.

– Components of the Sponge Filter

The sponge filter functions using two main components: the sponge and an air pump. The sponge also has a weighted base, so it sinks to the bottom when placed in the tank. Simultaneously, the air pump stays outside the tank to supply adequate air for the sponge to work.

Still, both sponge filter components are connected by a tube. Also, you should confirm that all components are the best fit for your tank size.

How To Assemble a New Filter Components

  • Take apart the sponge filter and remove the plastic strainer inside the foam
  • Next, remove the bullseye from the top of the plastic strainer and insert the air stone at its bottom
  • Using a small tube, connect the air stone to the middle of the bullseye or attach the air stone directly without the tube
  • Put the bullseye at the top part of the strainer and then place the strainer into the foam
  • Next, attach the strainer to the weighted base of a single sponge filter
  • Put the lift tube over the airline tube, then connect the airline tube to the top of the bullseye
  • Next, connect the lift tube to the bullseye

Step by Step Set Up

  1. Now that you have assembled the sponge filter, put the sponge filter into the tank.
  2. Then, squeeze the foam to let out air bubbles so it can soak in the water.
  3. Station the air pump outside the tank.
  4. Measure the length of the tube that conveniently connects the air pump to the sponge filter, then cut off any excess airline tubing.
  5. If you place the air pump below the top of the tank, check the valve as water could flow into the airline tube even when the air pump is turned off.

How To Make Your Sponge Filter Work Without Producing Loud Noise

The best way to make your sponge filter work without loud noise is to add an air stone. Here are some easy steps to add an air stone to your sponge filter:

  • First, you have to disassemble the sponge filter
  • Then remove the strainer and cut out the spokes in the middle
  • Take out the tube in it and connect the airline tube to the first one
  • Next, reassemble the sponge filter
  • Finally, connect the air pump to the sponge filter

How To Prevent Water Flow When the Air Pump Is Turned Off

  • Use a stopper valve
  • Alternatively, reduce the airline tube that connects the air pump and sponge filter.
  • Next, check that the end of the valve, which has the horizontal bar (flapper), is facing the air pump.

Why Are Air Bubbles Coming Out of the Side of My Sponge Filter and Inhibiting Its Efficiency

There are various reasons why air bubbles could be coming from the side of your sponge filter. Here are a few:

1. Inadequate Life Tube

Air bubbles are leaking from your filter because your lift tube is short or not properly connected. A short lift tube would not allow adequate suction so some bubbles would travel to the side and escape.

2. Crooked Air Stone

If your air stone is crooked in the sponge filter, air bubbles will leak at the side. So remedy it by reducing the length of the tube that connects the bullseye to the air stone.

3. Strong Air Pressure

If the air pressure produced by your air pump is too strong, it will force air through the filter, and some excess would leak from the side.

Make Your Filter Work Efficiently for a Longer Period

For your sponge filter to last, you need to maintain it by cleaning it. You can clean your aquarium sponge filter in the following steps:

  1. Remove the sponge filter from the tank and place it in a big ziplock bag
  2. Put some tank water into the bag enough to cause the filter to sink to its bottom
  3. Then lift the aquarium foam filter gently so you don’t dislodge the debris from the sponge
  4. Next, disconnect the airline tubing
  5. Put the Ziplock bag over a bucket
  6. Remove the plastic strainer, then squeeze the sponge into the bag
  7. Remember to wear gloves as the sponge would contain fish waste and decaying leftover food
  8. Empty the plastic strainer and clean it
  9. Then, remove the sponge from the Ziplock and pour the dirty water into the bucket
  10. You may need to squeeze the sponge against the bucket sides so more debris comes out
  11. Place the sponge back into the bag take out some water from the tank to rinse the filter again
  12. Repeat until the water in the Ziplock is no longer dirty
  13. Then, reassemble the sponge filter and place it back into the tank


1. How Often Do I Need To Clean My Aquarium Sponge Filter?

You need to clean your aquarium sponge filter at least once a month. Perform a deep clean once you notice it is clogged, and the air bubbles seem to have reduced. But please note that some fish species would generate more waste than others. Hence, every two weeks might suffice in some cases as a month’s wait may be too long.

2. How Often Do I Need To Change My Aquarium Sponge Filter?

You should change your aquarium filter every six months. However, this depends on how often you clean them. If you regularly clean your filter, you can use them for longer than six months until they begin to rip and break.

3. What Are the Benefits of Aquarium Sponge Filter?

Aside from the functionality benefits discussed above, having an aquarium sponge filter would offer the following advantages.

  • They are inexpensive compared to other aquarium filters
  • They are beginner-friendly
  • They are very productive
  • They are adaptable
  • They are available in most online and walk-in pet shops
  • They are durable

4. What Are the Types of Sponge Filter and What Tank Size Do They Efficiently Work For?

The sponge filter comes in a single or double format. However, they may have added functionality like an air stone.

– Single Sponge Filter

The single sponge filters are great for small-sized spaces, but some variants can be effectively functional in a 25-gallon tank. For an aesthetically pleasing tank view, you can opt to install the corner filter.

– Double Sponge Filter

The double sponge filters can suffice for any tank size. The small-sized double filter would cover up to 10-gallons while the larger double filter takes up to 55-gallons. Also, these variants have suckers, so they can easily be attached to the tank sides or below the substrates.

Furthermore, with the dual filter sponge in a new tank, you can replace one of the sponges with a new one. Then, use the old sponge to set up a breeding or quarantine tank. In no time, the bacteria colonies would be established.

5. Do Sponge Filters With Air Stones or Ceramic Bio-Filter Media work better?

These types of sponge filters are quite fancy but are not more effective. Some models of sponge filters have extra airline tubes, so you can buy air stones separately and add them to the setup. Nonetheless, the air stones help reduce the noise the sponge filter produces. Also, it further breaks down the air bubbles into much smaller sizes.

6. Does the Sponge Filter Really work?

Yes, the sponge filter works, but it has a few downsides. Here are a few of them:

– No chemical filtration

The first downside is the aquarium sponge filter’s inability to perform chemical filtration. It doesn’t include chemical media.

– Pre-filter

The sponge filter has been used for decades, but technology has since advanced. Still, it does an okay job, but some fish keepers consider them ineffective. Hence, some may use the filter as a pre-filter along with a modernized variant like the canister filter.

– Aesthetics

This last downside is not directly linked to the functionality of the sponge filter, but it is an issue some fish keepers face. The sponge filter is not attractive when used in the aquarium. No one wants an old sponge detracting from the elegance of their tank.

7. Can a Sponge Filter Work in a Crustacean or Fry Tank?

Yes, a sponge filter with air pump would work in a crustacean or fry tank. The filter generates a very gentle current, unlike other powerful filters. Some commonly powered filtrations use strong pressure, which sucks up debris, fish fry, or other tiny aquatic animals and kills them! Also, a smaller filter like the sponge filter has a slower turnover rate, yet would provide both mechanical and biological filtration.

8. Can I Put a Sponge Filter Work in My Planted Tank

Yes, you can. Indeed, it is beneficial because it houses bacteria that can be transferred to a quarantine tank. Furthermore, you can reduce the surface agitation it causes by adding an air stone. But, the sponge filter help converts ammonia to nitrite and nitrates which may be difficult for the plants to take up.

9. What Work Do Sponge Filters Do in a Fish Tank?

The sponge filter for fish tank is a good idea because it delivers various benefits. But, we will discuss in-depth the top three services that sponge filters provide.

  • Aeration
  • Biological filtration
  • Mechanical filtration

– Aeration

Sponge filter with air pumps provides a degree of aeration in the water column. This is quite important as it serves as an additional oxygen source in your aquarium. Fish requires oxygen to survive, and in some cases, the live plant in the tank may not efficiently supply enough oxygen naturally.

Also, when your tank is faced with algae bloom, the dissolved oxygen produced by the sponge filter would go a long way. Similarly, the beneficial bacteria that arise after cycling your tank are aerobic. They require enough oxygen to be effective at breaking down toxins from waste.

– Biological Filtration

How does a sponge filter workBiological filtration is a process whereby tiny bacteria colonies break down toxins in a tank. Unlike the negative view most people have when they hear about bacteria, some are useful. In this case, the bacteria grow on most surfaces in the tank, including the nooks and crannies of the sponge filter. The filter encourages the growth of these beneficial bacteria!

– Mechanical Filtration

Mechanical filtration is the sponge filter’s primary task. Apart from eradicating ammonia, phosphorus, and nitrites, there is debris that needs to be removed. Hence, the sponge filter gathers leftover food and other waste, leaving the tank clean and with great water quality.


Although the sponge filter is not considered modern or as efficient as newer filter models, they are not that bad. Hence, here are some pieces of information to remember about the sponge filter:

  • The sponge filter uses a frictional force to pull water through it
  • The sponge filter is easy to be installed, having two major component, the air pump and the sponge
  • It is very useful to the tank since it cleans the dirt that is in the aquarium, which helps the oxygen solubility for the fish

Furthermore, they offer other different benefits in a tank. For instance, they are inexpensive and easy to clean. Therefore, if you don’t already use one in your tank, get a single or double sponge filter today.

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