Find the Right Sponge Filter For Your Betta or Other Small Fish

Estimated read time 8 min read

Best Sponge Filter For Betta

The aquarium sponge filter may have a bad reputation as an ugly filter that doesn’t have enough filtration for most aquariums.

Though this may be true in some cases, when it comes to betta fish, the sponge filter is likely one of the best filters you could use. And when you use it as a Betta filter it’s even better.

In this post, we will cover everything you will need to know when selecting the best sponge filter for betta fish and even provide you with a few different options.

You can also click here to learn why you should always have a filter for your betta tank.

Our Top 4 Sponge Filters For Your Betta


 Here Are A Few Benefits Of The Sponge Filter

  • The most simple of all filters to use. They can run on basic air pumps or powerheads.
  • They provide excellent biological filtration.
  • The best filter for a Betta with their long fins as the filter won’t catch the fins
  • Inexpensive and cost-effective.
  • The best filter to use for breeding and hospital or quarantine tanks as they won’t suck up the fry or weak sick fish into the filter.
  • Very easy to clean. Remove the sponge and squeeze or rinse in old aquarium water.
  • Probably the best choice of filtration for delicate Discus or Angel tanks due to the fact that they do not attract noxious bacteria when used in a bare bottom tank.
  • Can be combined with most HOB filters as a pre-filter option.
  • Great for plants as they maintain higher CO2 levels in the aquarium.

Note: If you are considering using a Sponge Filter you will also require the following items:

  • An air pump
  • Some air tubing
  • Air Stone
  • Control Valve
  • Check valve (Optional)

All can be purchased on Amazon.

What Is A Sponge Filter (Bio sponge filter)?

A sponge filter is typically made up of an air tube and a porous spongy material that is used as the filtering mechanism.

Aquarium sponge filters can be used to provide biological & mechanical filtration of waste, byproducts and solid particles in the water.

It should be noted that sponge filters do not provide any form of chemical filtration.

However, you can always attach a carbon bag to the sponge when you need the chemical filtration, like after a treatment period. See example.

How Do Sponge Filters Work?

How do sponge filters work
Photo Via: Pet Resources

A sponge filter works by sucking water through a porous sponge which acts as the mechanical filter and traps any large debris in the water.

The spongy material also provides a great place for beneficial bacteria to grow. This beneficial bacteria will convert nitrates into nitrates which is less toxic to your fish and can be controlled/removed by regular water changes.

An air stone is used to create the suction which will draw the water through the sponge. You can also use a powerhead to create the suction effect.

This suction effect is called “uplift” and pulls the water through the sponge, filters it and discharges it back into your aquarium.

To give you an idea of when to use an air pump or powerhead see below.

Use an air pump when:

  • Hospital/quarantine tank
  • Breeding tank
  • When low flow filters are required.
  • Simplicity for beginners.

Use a power head when:

  • Higher flow rates are desired
  • Crosscurrent is necessary, especially for long tanks

Why Choose a Sponge Filter for Your Betta – Main Benefits.

  • If you are considering a planted tank sponge filters are a great choice as they remove far less CO2 from the water than HOB or Canister filters. Having more CO2 available for your plants will help your plants
  • Sponge filters provide a much more gentle current if using an air stone. This is great for small sensitive inhabitants like a Betta Fish, fish fry, or freshwater shrimp.
  • In many cases, sponge filters can provide much higher biological filtration.
  • Sponge filters can also be combined with HOB filters as a pre-filter. This helps keep the large debris from entering the HOB canister and also will allow the filter cartridges within the HOB to last longer.

The Only Two Negatives Of The Sponge Filter

  • One obvious negative of the sponge filter is how they look! Big bulky and ugly, your best to try to hide them behind some rocks or decor if possible.
  • Another drawback is their lack of chemical filtration which is typically done through the use of media like activated carbon.

However, as mentioned above if needed you can attach a bag of carbon to a sponge as needed when medicating your fish.

How To Use A Sponge Filter

In all honesty, there is nothing easier to use than a sponge filter. Most sponge filters are pre-assembled and all you need to do is attach an airline & a pump or a power head.

If you are going to use an air pump try using a Tetra Whisper Air Pump.

How To Set Up A Sponge Filter

Here’s a quick video by Thor’s aquatics on how to set up a sponge filter.

Best Sponge Filter For Betta Set Up

Thor gives a great overview of how to set up a sponge filter the right way and even shows you two options for control valve installation where you can run multiple sponges from one air pump.

How To Make A Sponge Filter In 4 Easy Steps.

If you are the DIY type you’re in luck because sponge filters are VERY easy to make. Here is a great video on how to make your own sponge filter.

How To Clean A Sponge Filter

When using a sponge filter regular maintenance is a must as one of the biggest problems with sponge filters is clogging.

In general, you should try to clean your sponge every two weeks. However, depending on the sponge type you are using and the bioload in your aquarium more frequent cleanings may be required.

You can always tell when its time to clean your sponge when the water around the sponge media begins to slow. This means you need to clean your sponge filter.

When you are ready to remove your sponge, place a small container or bowl below your sponge as you pull it out of your aquarium.

This will help prevent all the dirty water and debris from falling back into your aquarium as you pull the out filter.

Once the filter has been removed, all you need to do is fill up a small bucket with some used aquarium water. Then place the sponge into the bucket and give it a few squeezes until noting comes off the sponge.

Place the sponge back in your aquarium, dispose of the dirty water in the bucket and add new conditioned water as needed.

Learn More About Your Betta Fish

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