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. 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 find out about the various types of media and the functions they perform, as well as which media 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. Because it is porous, water can still flow though it. The size of pores determines the size particles that are trapped in the media.
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. To replace disposable filter cartridges in aquarium kits, we often use sponge pads.
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 can trap the smallest particles of flotsam, jetsam, and other debris in your aquarium. Because the floss pads are very dense by design, they can clog up easily and should be replaced when they turn brown in color. Both the coarse sponge pad and fine poly pad can be customized by cutting them into smaller sizes so that they fit your filter perfectly.
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. 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
bio rings
and bio balls) come with lots of porous or intricately patterned surfaces to serve as “housing” for the bacteria colony. The coarse sponge pads used to mechanically filter water are also a good place for beneficial bacteria to grow. Bio media’s shape allows water to flow freely through them, which in turn brings more oxygen to the bacteria. These surfaces can become covered in aquarium gunk over time. To clean them, gently wash or rinse them in old tank water until they fall off. 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 can remove certain chemicals and pollutants 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. To add chemical filtration, cut off a section of the pads and wrap it around a sponge filter. Once the charcoal pores are filled with pollutants, the activated carbon media is no longer functional and must be replaced.
A synthetic adsorbent such as Purigen is better if you want to use chemical filtration. The polymer granules come pre-packaged in a media bag, ready to absorb organic waste and tannins. The adsorbent’s color changes from white to dark brown and the pores must be cleaned. 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. 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.
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 you can layer your filter media. Here are some 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. 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. You can also use chemical filtration such as activated carbon and Purigen to filter the water before it leaves the filter. Not all of these products are necessary, but we do recommend having at least one layer of coarse mechanical filtration and then one layer of biological filtration if you have room.
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. If you are using Purigen, then chemical filtration should be replaced when it is finished. The frequency of maintenance will depend on several factors, including the size of your aquarium, the media used, and the food you feed it. As a rule of thumb, we recommend setting a calendar reminder to clean your filter 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 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. Measure the water to find out if chemicals filtration, such as ammonia media pads or phosphate pad, are used. If there are any tannins or unusual odors in your water, the activated charcoal should be replaced. If the water contains excess phosphate or ammonia, the chemical media pads will be ineffective.
Is activated carbon necessary for my aquarium filter? Since most chemical filtration is disposable, it cannot be reused. We like to keep it in reserve for those instances where we are certain that there are tannins or pollutants we want to get rid of. To ensure that the aquarium water is crystal clear, carbon can be used if you’re preparing for a photo shoot. Most hobbyists don’t use carbon every day because it is quickly depleted and can cause 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.