Biological filter media is any media that can be used to house as much beneficial bacteria as possible. Very porous media is desired because this will allow for more beneficial bacteria per square inch. Surface area is key when choosing the correct biological media.
So, what types of filter media make great biological filter media?
Porous ceramic cylinders
Ceramic cylinders are great biological media that you can add to just about any aquarium filter. Each cylinder will average 3/8”x 3/8”. Most often kept in media bags and kept as the last layer in your aquarium filter closest to the top. Ceramic cylinders allow for great water flow while providing exceptional surface area for your bacteria to grow and reproduce.
Bio-glass is very similar to the ceramic cylinders. Bio-glass is made of a natural silicate and is in the shape of a hollow cylinder. Most often kept in media bags and kept as the last layer in your aquarium filter closest to the top. Bio-glass allows for great water flow while providing exceptional surface area for your bacteria to grow and reproduce.
Bio-Balls are specially designed balls that are made to fit into your filter and house the much-needed beneficial bacteria colonies. One gallon of bio balls has the equivalent surface area of 21 ½ square feet. Works great in wet/dry and canister filters.
Quartz Biological Balls
Sphere shaped bio-media that is made from natural lava rock. Allows for great water flow while housing the much needed beneficial bacteria. Should be kept in aquarium filter media bags. Can be used in just about any aquarium filter.
A polymer material Biological filter media that is in the shape of a star. Provides excellent surface area to build up your beneficial bacteria. Four stars will treat 20 gallons.
Ehfisubstrat is a sintered glass that offers a huge surface area of nearly 19,000 square feet per gallon. Designed to house beneficial bacteria. Ehfisubstrat can be housed in many different aquarium filters. Can be added to aquarium filter media bags.
Biological Media Replacement
You may be thinking about how often you will have to replace biological filter media. Well, you probably will not have to! As long as the filter media is in good shape, and you are able to clean it, you should be OK. Most bio-filter media is reusable and only needs cleaning.
Cleaning Biological Media
How do you know if your biological filter media needs cleaning?
When you notice a great deal of detritus (fish waste and dirt) built up, or your water flow has slowed, you should clean your filter media.
You can wash out mechanical filter media under the faucet, but you should not wash your bio-filter media in this manner. Biological media needs to be washed out in a bucket of aquarium water. When you rinse your biological media out under a sink faucet, the chlorine will kill an beneficial bacteria you possess. Killing beneficial bacterial will lead to potential problems and possibly a mini-cycle. Always wash out bio-filter media in a bucket of aquarium water.