Gravity fed filters

From Koipedia

Gravity fed filters are the best kind because they allow debris such as leaves to flow from the pond by gravity into the filter without being emulsified (or ground up) by the pump as they are in Pump fed filter systems. Also they allow the pump to be located externally from the pond making it easier to access for maintenance and removing the requirement of a submersible pump which have several disadvantages over external non-submersible pumps.

The main disadvantages of Gravity fed filters is that they must be located so that the top of them (water level) is the same as the pond which can make it difficult to find a place for them. Also, a fair amount of plumbing must be done during the construction of the pond to allow the water to flow freely from the pond to the filter - typicaly from either a Bottom drain or a skimmer.

See also Pump fed filters See also Pressurized filters