Why are different pumps recommended for each filter?
We usually recommend two different pumps for use with each filter. The lower rated pump would be used where there is little pipework running from the pump to the filter and there is little difference in height between the pond water level and the filter, this difference is known as head. The higher rated pump is for use where there is a long distance between the pump and filter or a lot of bends in the pipe. The larger pump will also lift the water higher where larger head is required. Remember that every bend and device between the pump and filter as well as the pipe itself will reduce water flow. It is therefore better to go for a larger pump if in doubt, all the pumps we sell are adjustable and can be controlled further with a ball valve if required.
