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

Have you ever bought a new hang-on-back filter from the pet store and noticed that the instructions say you have to change out the filter cartridge at least once a 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. We will show you how to optimize your aquarium filter using just a pair of scissors.

Step 1: Purchase 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 will grow on any type of underwater surface, including gravel and walls. Prefilter sponges are a great way to encourage them 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?)

A prefilter sponge is a foam cylinder that fits over the intake tube of your hang-on-back or canister filter, like a sock on 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.

Pick an appropriately sized prefilter sponge for your filter, and you can easily double its filtration capacity.

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 the Disposable Carridge

At the beginning of the article, we mentioned that you should replace the default cartridge the filter comes with. It is so bad, you ask? 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 and fine filter carbon quickly absorb impurities and become very difficult to clean.

Step 3: Install the Reusable filter Media

Filter compartment (where the cartridge was supposed) should be filled up with coarse foam sponges 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. 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.

We use coarse sponge pads for mechanical filtration. These can be cut to fit any part of a hang-on back or canister filter. Because they are not easy to clog, can last for 10 years, and are relatively inexpensive, we offer coarse sponges. For biological filtration, you can use bags of bio rings that have lots of porous holes for beneficial bacteria to grow in. If the bag does not fit into the filter well, you can purchase a resealable media bag that contains enough bio rings to fill the entire filter.

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. The coarse sponge will remove most gunk from the water, and the bio rings with smaller pores won’t become as filthy.

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 coarse sponge. This will provide both mechanical and beneficial filtration.

Step 4: Clean the Reusable Media Filter

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?

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. These fine filter pads, like the cartridges will eventually have to be thrown away and replaced when they are clogged with debris. The advantages of these filters are that they are inexpensive 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.

Last Thoughts

Your aquarium system will be more efficient and maintain a high level of water quality by upgrading to reusable filter media. 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.