The best way to keep your fish healthy is to create an environment which is clean, healthy and balanced. If you are thinking about filtration – these are different options available.
Mechanical filtration systems ,remove debris from the pond water, by trapping it into the filter media.
Biological Filters help create beneficial bacteria, which will remove harmful pollutants from the pond water. The beneficial bacteria help create a balanced environment, to promote the nitrification cycle, the end product we are aiming for is nitrate.
A gravity fed filters, pushes pond water through the bottom drain and enters the filter along a length of pre-laid solid pipe. Water is pulled from the filter, which is installed at the same level as the pond, by a pump, then is passed through a ultra violet clarifier, before returning to the pond.
A pump fed system, has a pond pump in the pond, water is pumped up into a UV Clarifier, then into the filter and then gravity will return it back into the pond.
The size of the system, i.e. does the filter have the capacity to cope with the volume of pond water; you can never over filtrate!!!
Cost of the system, gravity fed systems are more expensive to set up, however the benefits are greater than a pump fed system