You need to learn about the different kinds of filters and what they do. You also need to know the three different kinds of "FILTRATION". Each one of these performs a different but very important function in your aquarium. All of these three types of "Filtration" involves the "Nitrogen Cycle".
Mechanical Filtration - This is the process in which particles or pieces of waste and uneaten food is filtered out of your water. Water is forced through your filter and it catches these pieces of stuff so your water stays clean. It is important to clean out your filter but remember to only rinse it in water you have taken out of your tank so you don't remove any of the "good" bacteria that has already formed on it.
Chemical Filtration - This is when toxic (poisenous) and/or unwanted chemicals are removed when the water passes through something called "filter media". Filter Media are things you put in a part of your filter (not all filters have them) to clean these chemicals from your water.
Biological Filtration - This filtration process involves the "Nitrogen Cycle". In Biological Filtration, different types of bacteria change the toxic chemical byproducts produced by the fish in your aquarium into less toxic nutrients.
It is important that you provide all three kinds of filtration in your aquarium. Let me explain the different kinds of filters you can buy and what they do.
Internal Filter - This filter sits inside your tank, usually on the bottom or sometimes in the corner. These filters usually need to be powered by an air pump. They do a good job on the Mechanical Filtration but are limited on Chemical and Biological because they don't get oxygen that is needed for the beneficial bacteria to survive on.
Undergravel Filters - These filters are put under the gravel on the bottom of your tank. They need an air pump attached to them to make them work. They can perform all three types of filtration but again are limited on Chemical and Biological because they are under the water and don't get the oxygen needed for the beneficial bacteria to grow.
Power Filters - These filters usually hang on the back of your aquarium and will perform all three kinds of filtration very well. You have to put a filter media in them which is usually like a foam pad for the water to strain out particles in the water. They also have their own pump so you don't have to have any other equipment to make them work.
