Koi

Pipework is required to feed waste-laden water from the pond into the filter and then transport the filtered water back into the pond. The choice of pipework is a vital element in ensuring the safe and effective maintenance of your pond.

Flexible hose is the cheapest and most versatile type of pipework, and is now available in long lengths of a variety of pipe diameters. It can easily be bent to cope with corners, without impacting upon flow velocity, although it can be difficult to fit it with the valves and accessories of complex Koi filtration systems.

So flexible hoses are most suitable for pump-fed filtration systems, where the need to install additional valves or fittings is limited. Rigid pipework is usually the most effective for gravity-fed filters where solvent-weld rigid pipework enables stronger and cleaner joints for drains and accessories such as UV clarifiers, and pump or filter fittings.

The velocity of water delivered by a section of pipe over a period of time is affected by a number of factors. While the pump is probably the biggest factor influencing waterflow within a pipe, it’s also influenced by the diameter, length and height up to which a section of pipe is expected to deliver water.

As a general rule of thumb, the output of a section of pipe will be reduced as the diameter of pipe is reduced, as the velocity of water passed through the pipe is reduced, as the length of pipe is increased and as the height up to which that pipe is expected to deliver the water is increased. While it is possible to calculate the impact of each of these factors, merely being aware of the impact of them will enable Koi keepers to reduce their impact and perhaps improve the performance of filters.

Written by Craig Baldwin

Photo courtesy of Keith Holmes