How to Upgrade an Aquarium Filter (and Save Money!)

Did you ever buy a new hang on-back filter from a pet store only to find out that it said you had to change the cartridge once per month? Most beginner fish keepers don’t realize that you can replace those disposable cartridges with reusable filter media that can last for the lifetime of the filter. In this article, we teach you how to optimize your aquarium filter in four simple steps, using only a pair of scissors.

Step 1 – Get a Prefilter Sponge

Beneficial bacteria are a naturally occurring form of biological filtration that consume the toxic nitrogen compounds produced by your fish’s waste, thus making the water safer for the fish to live in. They can grow on any surface underwater, even the gravel or walls of your aquarium. Therefore, one of the easiest ways to encourage their growth is to increase the amount of surface area in your tank with a prefilter sponge. (If you aren’t familiar with the three types of filtration – mechanical, biological, and chemical – you can read our article called Fish Tank Filters: Which One Should You Get?)

Prefilter sponges are foam cylinders that fit over the intake tube on your hang-on or canister filters. They look like socks on a feet. Not only do prefilter sponges grow lots of beneficial bacteria, but they also help with mechanical filtration by preventing food, small fish, leaves, and other large debris from getting sucked into the filter’s motor compartment.

Choose a suitable-sized prefilter sponge to your filter and you will easily double its filtration capability.

The prefilter sponge should be installed so that it covers the intake tube’s slits. This will ensure that the filter draws water out of the sponge to provide maximum filtration. To make it more snug, cut off some of the prefilter sponge. You should also make sure that you clean your prefilter sponge at least once a month if the water flow is declining.

Step 2: Dispose of the Disposable Cartridge

At the beginning of the article, we mentioned that you should replace the default cartridge the filter comes with. What is the problem? The fact is that most cartridges are made out of fine filter padding for mechanical filtration (to remove debris from the water) with activated carbon inside for chemical filtration (to remove medications and other impurities from the water). The problem is that activated carbon and fine filter pad quickly get clogged up with impurities and other waste. It’s also difficult to clean them and reuse them.

Step 3 – Install the Reusable Media Filter

Fill up the filter compartment (where the filter cartridge was supposed to go) with coarse foam sponge and bio rings. These media types can be reused, offer more biological filtration surface, and can even increase the filtration capacity by up to fourfold. As with the prefilter sponge, there is no need to constantly replace them and throw away all that beneficial bacteria; just rinse the filter media in old aquarium water once a month.

Coarse sponge pads remove debris from the water and can be reused by rinsing them on a monthly basis.

For mechanical filtering, we prefer coarse sponge pads. They can be cut to fit any area in a canister or hang-on-back filter. We offer coarse sponges because they do not clog very easily, are fairly low cost, and can last 10 years or more. Bags of bio rings with lots of pores for beneficial bacteria can be used to filter biological waste. You can buy a resealable medium bag for filtering and then pour the appropriate amount of bio rings into it.

Bio rings help boost the growth of biological bacteria, which consume the toxic nitrogen compounds produced by fish waste.

Find out the direction that the water flows through your filter media before you install it. AquaClear filters are an example. The water flows upwards from its bottom to the top, then falls back into the aquarium. Place the coarse sponge pad on the bottom of the compartment, so that the water hits it first. Then place the bio rings above the sponge. So the water will not get clogged up and the sponge (which has larger pores) won’t get so dirty.

If you have a nano tank for your betta fish that comes with a built-in filter compartment, you may not be able to fit as many layers inside. The disposable cartridge should be replaced with only coarse sponge. This will provide both mechanical and beneficial filtration.

Step 4: Clean the Reusable filter Media

Regular maintenance is important. Rinse the filter media at least once per month. Mechanical filtration (such as prefilter sponges and sponge pads) acts like a garbage can that collects waste – which means you as the fish owner are still responsible for cleaning the filter media (in other words, “emptying” the trash can before it overflows and causes water to spill out of the aquarium).

How Do I Upgrade My Filter to Get Crystal Clear Water?

To really polish the water add a layer if fine poly pad. This has very small pores which can remove any particulate. The fine filter pads need to be replaced after they have become contaminated with debris. However, the advantages are these pads are very cheap and can be cut to any size.

Poly pads are great at removing fine particles so that you get crystal-clear water and your fish look like they’re flying in midair.

Final Thoughts

Reusable filter media can make your aquarium system more efficient and help maintain high water quality. The upfront cost may be a little more at first, but reusable filter media tends to last for the lifetime of the filter, saving you a lot of money in the long run.