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 is the various layers of materials through which aquarium water is filtered before being returned to the aquarium. Continue reading to learn more about the different types of media available, their functions, and which ones should you use.
1. Mechanical Filter Media
Mechanical filtration is made up of foam pads, sponges and filter floss. These filter out any particles from the water much in the same way as 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.
You can add a fine Poly pad to your aquarium to remove any tiny particles. This mechanical filter media has very fine porosity that can catch the tiniest bits of flotsam and jetsam in your aquarium. Because floss pads have a dense design, they are easy to clog and should be replaced once they turn 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 pads (right) are used 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. Since beneficial bacteria can grow on any surface of the tank that is well oxygenated, the filter is a prime location to increase the population. Biological media (such as
bio rings
and bio balls) come with lots of porous or intricately patterned surfaces to serve as “housing” for the bacteria colony. Beneficial bacteria can also grow on the sponge pads that are used for mechanical filtering. The shape of the bio media also allows water to flow freely though them to bring more oxygen to the bacteria. Aquarium gunk can cover these surfaces over time, so clean the bio media every 1-3 months by gently waving or rinsing it in old tank water until the debris falls off. (If you are using loose bio media that does not come in a bag, put it in a filter media bag to make it easier to pick up and clean.)
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 easier to handle, can be cut down to a custom size, and provide increased mechanical filtration for straining debris from the water. To add chemical filtration, cut off a section of the pads and wrap it around a sponge filter. Once the charcoal pores become clogged up with pollutants, activated carbon media cannot be used again and must be replaced.
You can also get synthetic adsorbents like Purigen if you prefer chemical filtration. The pre-packaged polymer granules are ready to absorb organic and chemical waste. The adsorbent’s color changes from white to dark brown and the pores must be cleaned. Follow the manufacturer’s instructions to create a diluted bleach solution that burns off the organic impurities so that the Purigen bag can be reused again.
Certain types of filter media are made to target specific chemicals and filter them out. 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. Try using a phosphate media pad to keep the phosphate under control so that algae can’t take advantage of 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
Filter Media: Commonly Asked Questions
What order should I put the aquarium filter media?
There are many ways to layer the filter media in your filter, so these are our general suggestions. The first step is to look in the manual and find out which 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. As a final mechanical filtration layer, you have the option of adding the fine poly pad to catch even smaller particles floating in the water.
The next layer is the biological filtration, so fill the media trays with bio media. Finally, you can choose to use chemical filtration like activated carbon or Purigen at the very end right before the water leaves the filter and reenters 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 do I clean an aquarium filter without killing bacteria? Remove the filter media and rinse them in old aquarium water or dechlorinated water to remove any accumulated waste. 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). 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, such as activated carbon or bio media, in a filter bag to make it easy to transport and contain.
How long does aquarium filter media last? Reusable filter media – such as the coarse sponge pad, bio rings, and Purigen – can last for many years, as long as it can be cleaned sufficiently so that its functionality is not impaired. Fine poly pads should be disposed when they turn brown in color and water cannot move through them as easily. Measure the water to find out if chemicals filtration, such as ammonia media pads or phosphate pad, are 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 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.