How To Use Aquarium Sponge Filters | Aquascape Addiction

How To Use Aquarium Sponge Filters

As an Amazon Associate I earn from qualifying purchases.

Questions about aquarium sponge filters? this article covers the ins and outs of them from how to use them, pros, cons and much more.

How To Use Aquarium Sponge Filters

Now, you probably know what most of the filter types are for aquariums. However, one type of filter that often gets overlooked is the sponge filter. While the sponge filter is not all that well-known and not hugely popular, it does have some good uses and benefits.

How to use an aquarium sponge filter might seem like an odd thing to talk about, but we have much more than just that. Today we want to talk about aquarium sponge filters in general, what they are, what they do, how you use them, and much more. So, let’s not waste any more time and get right to it.

What Is An Aquarium Sponge Filter?

As the name implies, an aquarium sponge filter is a filtration tool used to clean the water, one which uses a sponge in order to filter out debris and other things too. A sponge filter uses some kind of air pump or water pump do draw water through a sponge which acts as the filter.

These sponge filters can be located on the inside of the aquarium tanks walls and or be placed under the substrate as well. They are really not all that different from other types of filters in terms of their function.

Simply put, they use some kind of method to draw water through the filtration mechanism, which in this case is a sponge, to filter out debris and other unwanted substances, eventually returning the clean and clear water into the tank.

Sponge filters in some cases can be connected with other filtration units for some really clean and clear water. The cool part about sponge filters is that sponges can come in different shapes, sizes, and with different sized pores, thus making them very versatile and adaptable to varying filtration needs.

What Does An Aquarium Sponge Filter Do?

Ok, so we know that a sponge filter is a filter, but what exactly does it filter out? Well, first off all, the sponge acts as a mechanical filter. This means that it filters out solid debris like uneaten food, fish waste, and other small particles out of the water.

The smaller the pores on the sponge, the smaller the particles that it can capture, but it does mean a slower going due to less water flow. In other words, the main purpose of a sponge filter is mechanical filtration.

However, that is not all because a sponge filter also acts as a biological filtration unit. Biological filtration is essential for the health of any fish tank, whether saltwater or freshwater. You see, fish waste releases a lot of ammonia, which is deadly to fish and plants even in small quantities (more on lowering ammonia levels here).

Biological filters, by having beneficial ammonia eating bacteria, help to degrade and break down the ammonia into nitrite, which is still harmful to fish. Yet, those same bacteria then break down the nitrite into nitrate, which is less harmful to fish. That being said, an aquarium sponge filter does not engage in chemical filtration. So, simply put, a sponge filter is a mechanical and biological filtration tool used in various aquarium setups.

Aquarium Sponge Filters – Use & Maintenance

Ok, so asking how to use an aquarium sponge filter is not exactly a question that is easy to answer, mainly because there are some differences between models. Simply put, you need to mount the sponge on an aquarium wall or under the gravel, you need to connect the intake and outtake tubes for the water, the mechanism which pulls the water though the sponge, and you need to hook up the power too.

However, your best bet is to simply read the instructions on the packaging of the specific sponge filter you got for the ideal setup.


Now, when it comes to maintenance, luckily sponge filters don’t require too much of it, plus it is fairly easy to do as well. You will want to clean the sponge regularly, anywhere from every week to every four weeks.

These sponges get visibly dirty, so it is not hard to tell when cleaning is need. Also, keep in mind that the amount of fish, plants, food, and other factors present in the tank will affect how often the sponge filter needs to be maintained.


The easiest way to clean an aquarium filter sponge is to remove some of the aquarium water and place it in a bucket. Take the sponge and squeeze it in and out for a few minutes until you are satisfied that all of the debris and particles have been removed and flushed out.

Water / Bacteria

The reason you want to use existing aquarium water to do this is because of the bacteria. If you use water other than that in your aquarium, you will be killing off and removing the beneficial bacteria needed for biological filtration, and you will have to wait for them to grow back and multiply.

However, if you do need to use clean water, such as could be the case if you are doing a water change due to really dirty water, you need to let the sponge soak in the aquarium water after rinsing it out in order to get some bacteria back into it. Other than that, you might need to flush out the intake and outtake tubes every now and again, but there is not much else to be done in terms of maintenance.

Uses For Sponge Filters

There are several different situations where you might find that a sponge filter is the best way to go. So, what are these situations where your best option might just be this odd little filtration tool?

  • If you have fish or animals that do not do well in a strong current, a sponge filter will do well. Animals like betta fish, other slow swimming fish, and even shrimp do not like strong currents. Sponge filters create minimal currents are therefore ideal for these kinds of fish, plus this also makes them ideal for breeding tanks where many small fry will be present.
  • Sponge filters are also ideal for tanks with many really small creatures that may be sucked up by other filters. Since these have a slow flow rate, they are not likely to suck up any creatures in your aquarium.

  • The low flow rate and currents created by sponge filters also make them ideal for hospital and quarantine tanks. Weak fish can’t handle strong currents, but they still need their water to be filtered, thus making the sponge filter an ideal choice.

  • Sponge filters are also ideal for colonizing fresh tanks with beneficial ammonia killing bacteria. You can use a sponge in an aquarium, let it build up with bacteria and then transfer that same water soaked sponge into a freshly established tank. This will go a long way in cycling the tank and will immediately introduce beneficial bacteria into your new setup.

  • You can also use a sponge in canister filters. They act as a good mechanical and biological filtration tool, so adding a small sponge or two into the media trays of your canister filter is not a bad idea either.

The Cons Of Sponge Filters

There are a couple of drawbacks to aquarium sponge filters that you might need to know about. First off, they do only engage in 2 of 3 types of filtration which most people would consider necessary for a fish tank to thrive.

No Chemical Filtration

While they do a great job in terms of mechanical and biological filtration, they absolutely do not engage in any chemical filtration at all. This means that certain odors, colors, and other substances may not be fully removed from the water.

That being said, most people would also agree that a really strong and efficient mechanical/biological filter can make up for a lack of chemical filtration.

Visual Appeal

The other negative aspect of these sponge filters is that they just don’t look very nice. After all, it is a sponge and unless you have a lot of plants to hide it in the background, it is fairly visible. This is a minor drawback, but it is one that people tend to mention when they talk about sponge filter cons.


As you can see, while sponge filters do lack chemical filtration abilities, they are still great choice to go with for a variety of situations. We hope that this article has helped you figure out exactly what a sponge filter is, what it does, and how you can use it to keep the water in your aquarium as clean and clear as can be.