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

You may have noticed in the instructions that you need to replace the filter cartridge every month if you buy a hang-on-back filter at the pet shop. 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. We will show you how to optimize your aquarium filter using just 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. A prefilter sponge is one of the best ways to encourage their growth. (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 a foam cylinder that fits around the intake tube of your canister or hang-on back filter. It is similar to a sock for a foot. 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.

You can double the filtration power of your filter by choosing a prefilter sponge that is appropriate in size.

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. However, if you find your prefilter sponge is a little too loose, you can cut off a sliver of sponge and stuff it down the center hole to make a snugger fit. 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 the Disposable Carridge

At the beginning of the article, we mentioned that you should replace the default cartridge the filter comes with. Why is this so terrible? 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). Unfortunately, activated carbon and fine filter padding quickly get clogged up with impurities and waste, reducing their effectiveness. Also, their dense materials can be difficult to clean and reuse.

Step 3: Install the Reusable filter Media

Fill up the filter compartment (where the filter cartridge was supposed to go) with coarse foam sponge and bio rings. These filter media types are reusable, have much more surface area for biological filtration, and can increase the amount of capacity filtration by up to four times! You don’t have to replace the filter media or throw away any beneficial bacteria. Just rinse them in old aquarium water once per month.

Coarse sponge pad removes debris from the water. They can be re-used by simply rinsing them every month.

For mechanical filtration we use coarse sponge pads. You can cut them to fit any space in a hang on-back filter or canister filter. They are durable, cost-effective, and last up to 10 years. Bags of bio rings with lots of pores for beneficial bacteria can be used to filter biological waste. If the bag doesn’t fit perfectly into the filter, you can also buy a resealable filter media bag and pour the right amount of bio rings that will fit inside the filter compartment.

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

In order to install the filter media, find out which direction the water flows through the filter. AquaClear filters, for example, allow the water to flow upwards from the bottom to the top of the filter and then 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. This will allow the coarse sponge to remove most of the gunk and also ensure that the bio rings, which have smaller pores, don’t get as 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. We recommend replacing the disposable cartridge with coarse sponge. This provides both mechanical and beneficial filtering.

Step 4: Clean the Reusable Media Filter

Make sure to regularly maintenance your filter and rinse the filter media once a 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 can I upgrade my filter for crystal clear water?

If you want to really polish the water, simply add a layer of fine poly pad that has very small pores and is capable of removing tiny particulate. The fine filter pads need to be replaced after they have become clogged up with debris. These pads have the advantage of being very affordable and easily 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. Although it may cost more upfront, reusable media can last for many years, which will save you lots of money over the long-term.