Keeping those colonies healthy, or optimizing the amount of bacteria in the tank can be a function of the type of filtration equipment that you choose to use. Filtration Equipment Determining the right filtration equipment is one of the most confusing but important choices that you will need to make. Essentially, aquarium filters work in three different ways. Biological filtration takes advantage of the natural bacterial process involved in the nitrogen cycle. Biological filters provide larger surfaces for beneficial bacteria to colonize, ensure that water passes through the colonies, and help to protect those bacteria from being disturbed.
Mechanical filtration removes unsightly particles from the tank.
This may include fish excrement, sludge, uneaten food, dust, or the like. Tank water is passed through a mechanical filter, and the particles are strained out. To prevent buildup, the filter media must be cleaned regularly. Some waste in the tank may be dissolved in the water, and a mechanical filter cannot take care of this problem. Chemical filtration is how these dissolved wastes are removed from water.