How to Customize your Aquarium Filter With Filter Media


How to Customize Your Aquarium Filter with Filter Media

Because aquariums are so different in size and stocking levels it is natural that they want to be able to adjust the filtration to their specific needs. Most filters – such as hang-on-back (HOB), corner box, internal, canister, and sump filters – can be modified by changing the types of filter media used inside. Filter media refers to the different layers of materials that tank water gets filtered through before returning to the aquarium. 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 consists of sponges, foam pads, and filter floss that physically strain out debris from the water, much like a coffee filter. The pores in mechanical media are porous, so water can still flow through them. Also, the size of the particles caught in the material determines how big they will be.

Use coarse sponge pads

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. You don’t need to keep them clean as they don’t clog quickly. We often use sponge pads to replace the disposable filter cartridges that come with many aquarium kit filters.

If you’re still seeing tiny particles floating in the aquarium and want to get crystal clear water, try adding a fine poly pad or filter floss. This mechanical filter media has very fine porosity that can catch the tiniest bits of flotsam and jetsam 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 (or bio balls) have porous or intricately-patterned surfaces that provide “housing” to the bacteria colony. 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. To make it easy to clean, you can use loose bio media without a bag.

Aquarium bio rings for biological filtration

3. Chemical Filter Media

Chemical filtration is able to remove contaminants and some chemicals from water. The most popular is activated charcoal, which is a porous carbon that easily absorbs medications, tannins, as well as other impurities. Activated Carbon for Aquariums is typically supplied loose granules that must be placed in a filter bag. We prefer using

carbon-infused media pads

because they are easier to handle, can be cut down to a custom size, and provide increased mechanical filtration for straining debris from the water. 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.

If you prefer to have reusable chemical filtration, get a synthetic adsorbent like Purigen instead. The pre-packaged polymer granules are ready to absorb organic and chemical waste. Once the color of the adsorbent turns from off-white or dark brown, it is time to clean the pores. Make sure to follow the manufacturer’s instructions and use a bleach solution to remove 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. When keeping live aquarium plants, some planted tank articles recommend keeping approximately 0.5-2.0 ppm phosphate for healthy plant growth, so don’t remove too much phosphate or else you may see yellowing and browning in the leaves.

Phosphate, ammonia and carbon-infused pads for chemical filtration

Frequent Asked Questions about Filter Media

Which order should I place the aquarium filter media in?

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. We like to use a coarse sponge to filter out large particles of debris as they enter the filter media basket. You can also use the ammonia and phosphate media pads here for mechanical filtration. To capture smaller particles suspended in water, you can also add the fine poly pads to your final mechanical filter layer.

Next, you can use biological filtration. Fill the media trays and media with bio media. Finally, chemical filtration can be used at the end of the filter just before water exits the aquarium. Although not all these products are required, we recommend at least one layer each of coarse mechanical filtration as well as one layer of biological filter if there is enough space.

How can I clean an aquarium filter that doesn’t kill bacteria? Rinse the filter media in old aquarium water. The dirtiest sponge pads can be wrung vigorously to remove as much as possible. Bio media contains beneficial bacteria. They should be gently agitated in the water and not scrubbed. Chemical filtration needs to be replaced entirely when used up (unless you’re using Purigen, which can be cleaned with diluted bleach). It depends on the size and media of the filter as well as the amount of food that is being fed to it. As a general rule, it is a good idea to set up a reminder in your calendar to clean your filters every 1-3 months.

Place loose media, such as activated carbon or bio media, in a filter bag to make it easy to transport and contain.

How long can aquarium filter media last? Yes. Reusable media, such as Purigen, Bio Rings, and coarse sponge pads, can last many years as long as they can be maintained properly so that it does not compromise its function. Fine poly pads should be disposed when they turn brown in color and water cannot move through them as easily. The only way to tell if chemical filtration like activated carbon, ammonia media pads, and phosphate pads are spent is to measure the water. 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 require carbon in my aquarium filtration? Activated carbon, like most chemical filtering, is disposable and cannot re-used. However we keep it for special occasions when we are aware of any tannins or pollutants that we need to remove. To ensure that the aquarium water is crystal clear, carbon can be used if you’re preparing for a photo 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.