Filtration Media Types

Filtration MediaFilter media is used extensively throughout the life of your aquarium and it is always a good idea to know what you need to keep fish healthy and alive. To filter water all you need is a medium for water to pass through, and this medium has to create an environment for bacteria to thrive. This beneficial bacteria – nitrifying & denitrifying, will convert the toxic ammonia in the waste to less harmful nitrate through the nitrogen cycle.

  • Nitrifying bacteria are aerobic, using available oxygen to convert ammonia to nitrate.
  • Denitrifying bacteria are anaerobic and convert ammonia into nitrogen gas without the use of oxygen reducing the nitrogen load in the aquarium.

Over time filters will clog up with excess decaying matter and will need to be cleaned. Cleaning a filter thoroughly is not necessary as this will remove too much of the already beneficial bacteria that you have accumulated. Better to remove only, the excess build up of this decaying matter and debris allowing a clean constant flow back through the filter. This will help keep a stable environment for your fish. The filter needs to be on at all times because no flow through the filter, means no oxygen for your aerobic bacteria.

After cleaning your filter media, some beneficial bacteria is removed. New colonies will need to multiple again. This may cause an ammonia spike while they are repopulating, as there are not enough bacteria to consume the amount of ammonia presently in the water. Always use water from your aquarium to clean any parts from your tank. This will help to not kill off the colonies of microbes and bacteria you have acquired, through chlorine and other chemicals commonly found in tap water.

Bacteria colonies will grow to the amount of available food – ammonium, ammonia and nitrite in the water. Every filter will work to some degree but the efficiency will depend on the amount of media and the media used. The same principal can be applied to different filters. Water flows in, travels through the media then back out. Setting up your filter media the right way ensures maximum build up of beneficial bacteria. It is best to put the media in the right order to help the biological media be as clean of debris as possible. Mechanical, Chemical then Biological.

1. Mechanical filtration to help remove any excess debris.

2. Chemical filtration to help with the removal of excess toxins in the water.

3. Biological filtration to create a colony of beneficial bacteria that will consume ammonium, ammonia & nitrite.

1. Mechanical Filtration Media

Filter Wool or filter floss is a polyester fibre material that will help trap fine particles and detritus from your filter to reduce clogging further down the line helping in nitrate reduction. There are different grades of filter wool. Less dense usually will deteriorate quicker than a denser stronger grade. A denser grade wool will sit better in the filter and can be rinsed and reused multiple times. Filter wool will help to promote crystal clear water.

Sponge or Foam can be used as a sponge filter or as mechanical filtration. Its porous open cell design allows larger debris to be trapped before traveling any further. Sponge gets clogged easily so it will need to be cleaned regularly. This can be used over and over again. It does not have to be cleaned to the point where it looks brand new. Quite the opposite, lightly rinse to get rid of the excess build up of waste and put back in. Every time your sponge is cleaned beneficial bacteria is reduced significantly. Best to use a sponge filter in a planted tank as plants will help absorb any ammonium that may be present after a filter clean.

Bio foam is also available. The pore structure of the foam is slightly different allowing nitrifying bacteria to colonize more easily on the foam.

There are a multitude of foams and filter wool on the market that are chemically impregnated – infused with carbon, phosphate remover etc to help remove certain toxins from the aquarium. This is useful if you are tight on space.

2. Chemical Filtration Media

Chemical media is best used in assistance with your already functioning biological filtration media.

Phosphate Remover aids in the removal of Phosphate and Silicate. The building blocks of algae.

Ammonia Remover helps to remove toxic ammonia. Use after a filter change or when you have a higher than expected fish load.

Activated Carbon removes odours, heavy metals, toxins, dissolved organics, discolouration, medications. It is beneficial to remove carbon once it has served its purpose. There is a debate, whether Carbon should constantly live in the filter or only used on occasion. This is because it will remove organic compounds from the water regardless of whether they good or bad for the aquarium.

Resins are designed to adsorb phosphate, nitrite and nitrate. Again very helpful in the removal of these toxins.

Coral Sand will help raise pH and Hardness of the water. Ideal if you have soft and acidic tap water. This will help raise and hold the water at a more alkaline level which is more suited for fish living in these conditions. Needs to be cleaned around every 6 weeks to ensure removal of bacteria build up so it can continue to leech dissolved minerals effectively.

Peat moss will help to lower pH and soften water. Ideal if you have harder more alkaline tap water. Will turn your aquarium water a slight tea colour. Helps promote breeding in soft water fish.

3. Biological Filtration Media

Bio Balls are filtration media made of plastic that come in many different designs. Bio balls have a lot of surface area to maximize the amount of bacteria growing on them. They have rough surfaces and water can pass through them quite easily allowing a constant flow of aeration throughout. This will help keep nitrifying bacteria alive. Bio balls generate the aerobic conversion of ammonia into nitrate. They are light weight and can be used in almost any filter or sump. Perfect in trickle filters as the bio balls are provided with plenty of aeration. These are great for fish and planted aquariums.

Ceramic Rings are very porous and contain millions of tiny pores. Because of this rough texture it allows bacteria to colonize faster. The surface area of ceramic rings is larger than bio balls, allowing a lot of area for beneficial bacteria to thrive. Due to the amount of small pores throughout media some of them will become clogged over time and create anaerobic zones. This will also help to reduce the ammonium load on the aquarium. Ceramic rings are great to use when you have a high fish load.

Sintered Glass is extremely efficient as a biological media due to its ability to house plenty of beneficial bacteria. It’s pores are larger and more absorbent than other medias. It provides an even distribution of aerobic and anaerobic bacteria. For the same amount of space you can have far more bacteria growing in the filter. Every bit helps when keeping fish healthy and you will have far less problems. Sintered glass can also contain trace elements speeding up the colonization of beneficial bacteria. Great to use for both fish and planted aquariums.

Moving Bed media creates a lot of aerobic microbes and beneficial bacteria. This filtration media is probably the most efficient in converting ammonia to nitrate. This is due to it its light weight which is circulated continuously with an air pump. The media crashes together removing any dead organic material and only retaining the beneficial bacteria. Large surface area to support micro organisms and aerobic bacteria. It will turn brown once colonized. Not as good for a planted tank as it doesn’t leave any free ammonium for plants. Also a lot louder if using in a sump. Great to use for a high fish load.