How to Customize your Aquarium Filter With Filter Media


How to Customize Your Aquarium Filter with Filter Media

Aquarium sizes and stock levels can vary widely so it makes sense for people to have the ability to tailor the filtration to suit their needs. You can modify most filters such as the hang-on back (HOB), cornerbox, internal, sump and canister filters by changing the type of filter media inside. The different layers of media that aquarium water passes through before it returns to the tank are called filter media. Keep reading to learn about the different kinds of media, the functions they serve, and which ones you should use.


1. Mechanical Filter Media

Mechanical filtration uses sponges, foam pads and filter floss to physically remove any debris from the water. It is similar to a coffee filter. Because it is porous, water can still flow though it. The size of pores determines the size particles that are trapped in the media.

Sponge pads made of coarse sponge

with large pores are good for blocking most debris like fish poop and dead leaves, and when they become full of waste, you can squeeze them out in old tank water and reuse them over and over again. They don’t clog as quickly so you don’t have to clean them as often. Sponge pads are often used to replace the disposable cartridges included with aquarium kit filters.

If you still see tiny particles floating around in your aquarium, or want crystal clear water, add a filter floss or fine poly pad. This mechanical filter media can trap the smallest particles of flotsam, jetsam, and other debris in your aquarium. The floss pads are extremely dense and can cause clogging. They should be replaced if they become brown. The coarse sponge pad and the fine poly pad can both be cut into smaller sizes to suit your filter.

Fine poly pad (left) and coarse sponge pad (right) for mechanical filtration

2. Biological Filter Media

Biological filtration refers to the usage of beneficial bacteria and aquarium plants to consume the toxic nitrogen chemicals generated from fish waste, thus purifying the water. Because beneficial bacteria grows on any surface area in the tank that is well-oxygenated, the filter is a primary location to boost the population. Biological media (such

bio rings

Bio balls and bio sponges have many porous or intricately pattern surfaces to provide housing for bacteria colonies. The coarse sponge pads used to mechanically filter water are also a good place for beneficial bacteria to grow. The bio media is also designed to allow water to flow freely between them. This allows for more oxygen to be delivered to the bacteria. Aquarium gunk can build up on these surfaces so you should clean it every 1-3 months. You can gently rub the surface with old tank water or waving it until any debris is gone. If you’re using loose bio media, place it in a filter bag to make it easier for you to pick up.

Aquarium bio rings for biological filtration

3. Chemical Filter Media

Chemical filtration can remove certain chemicals and pollutants from water. The most common type is activated carbon, which is a highly porous charcoal that readily absorbs medications, tannins, and other impurities. Activated carbon is usually supplied in loose granules for aquariums. They must be kept in a filter media bag. We prefer using

Carbon-infused media pads

Because they are more manageable, they can be reduced to a specific size and offer increased mechanical filtration to remove any debris. For added chemical filtration, you can cut a portion of the pad and wrap it around a sponge filter using a zip tie or rubber band. Once the charcoal pores are filled with pollutants, the activated carbon media is no longer functional and must be replaced.

You can also get synthetic adsorbents like Purigen if you prefer chemical filtration. The polymer granules come pre-packaged in a media bag, ready to absorb organic waste and tannins. Once the color of the adsorbent turns from off-white or dark brown, it is time to clean the pores. To clean the Purigen bag, follow the manufacturer’s instructions. Use a bleach solution to burn off organic impurities.

Filter media can be designed to filter out certain chemicals. For example, ammonia spikes are prone to occurring when the balance of your fish tank has been disrupted, such as after moving an aquarium, experiencing a power outage, or thoroughly cleaning a fish tank. To prevent toxic levels of ammonia from building up, you can preventatively install an ammonia filter pad to absorb the ammonia and keep your fish safe.

If phosphate levels are excessively high in your aquarium, it can lead to algae growth and compromise your fish’s health. Use a phosphate pad to control the phosphate so that algae doesn’t get it. For healthy growth of live aquarium plants, a few articles suggest keeping 0.5-2.0ppm phosphate. If you don’t want to see yellowing or browning, it is best to keep the phosphate under control.

Ammonia- and carbon-infused phosphate pads for chemical filtering

Frequent Asked Questions about Filter Media

How should I arrange the aquarium filter media?

There are many ways to layer the filter media in your filter, so these are our general suggestions. Look in the manual to find the direction the water flows through the filter. To prevent large chunks of debris from getting into the filter media, we recommend using a coarse sponge pad to mechanically filter the water. These pads can be used as mechanical filtering if you have to use ammonia orphosphate media pad. You can add the fine poly pad as an additional layer of mechanical filtration to capture even smaller particles in the water.

The next layer is the biological filtration, so fill the media trays with bio media. Finally, chemical filtration can be used at the end of the filter just before water exits the aquarium. While not all products are required, we recommend that you have at least one layer in coarse mechanical filtration followed by one layer in biological filtration.

How can I clean an aquarium filter that doesn’t kill bacteria? Rinse the filter media in old aquarium water. You can use the coarse sponge pads to clean it. Bio media houses beneficial bacteria and should be gently agitated (not scrubbed) in the water. Except for Purigen which can be washed with bleach, chemical filtration must be completely replaced. The frequency of maintenance will depend on several factors, including the size of your aquarium, the media used, and the food you feed it. We recommend that you set a reminder on your calendar to clean your filter once every three months.

Place loose media (like activated carbon and bio media) in a filter media bag to make it easier to contain and move around.

How many years does aquarium filter media usually last? As long as it is clean enough to not impair its functionality, reusable filter media such as coarse sponge pads, bio rings and Purigen can last many, many years. If fine poly pads turn brown and water can’t pass through them, they should be disposed of. You can only measure the water to determine if any chemical filtration such as activated carbon, ammonia pads, or phosphate pads has been used. It’s time for you to replace activated carbon if there are tannins or other unpleasant odors present in your water. If you are measuring ammonia or excess phosphate in the water, then the chemical media pads are likely saturated and no longer functional.

Do I need carbon in my aquarium filter? Because activated carbon (and most chemical filtration) is disposable and cannot be reused, we like to save it for specific instances when we know there are pollutants or tannins that we wish to remove. You may use carbon to make sure the water is clear when you are getting ready for an aquarium shoot. But, hobbyists tend to not use carbon on an everyday basis as it can quickly become depleted and may only see temporary results.

To take your fish tank filtration to the next level, learn how to upgrade your aquarium filter with filter media in four easy steps.