Aquarium equipment – The filter

The filter

The filter is the heart of your aquarium. The filter keeps the balance of chemicals right in the water by providing a place for beneficial bacteria to live.

Before deciding to set up an aquarium you should take a quick look at fish-less cycling to find out how to get these beneficial bacteria. Once you have that established the filter, it will be your best friend and will store all the beneficial bacteria that are keeping your water right.

To get this bacteria growing you need to let the nitrogen cycle begin. The cycle begins with dead plant matter and fish waste which produce ammonia (extremely toxic to fish). Some of the ammonia will be used up by plants but most of it is converted into nitrites (highly toxic to fish), by bacteria which lives in the filter. Nitrite is then converted into Nitrates by the bacteria in the filter. Nitrates are removed from the water by plants and water changes.

The filter has 3 main aspects to filtration which each perform different functions, these are:

• Mechanical Filtration – This filtration removes solid particles from the water. It does not remove ammonia, nitrite or nitrates. Common types of media are sponges, floss and paper cartridges.
• Biological Filtration - This filtration is the beneficial bacteria which are established during cycling. These bacteria break down ammonia, nitrites and convert them into a less toxic compound, nitrate.
• Chemical Filtration - This filtration removes dissolved wastes. The most common type of chemical filtration media is activated carbon.