Types of Water Pumps for the Garden Pond
Pumps come in a variety of sizes and in two types, the submersible and the surface pump. Choose one that is suitable for the amount of water to be moved and the height it has to be lifted. The manufacturers usually give the pump output with the varying heights it can be used, in either litres or gallons.
A small pump will provide a gentle flow of water suitable for the small pond, but a bigger pump will need a larger pool to move more water without causing too much turbulence in the pool. A large pump can give a powerful gush of some five times the flow of a smaller pump. The fountain can also vary from a single jet of great power to a cluster of sprays of a more modest height. When choosing, keep in mind the scale of the garden: a small spray would look pathetic in a lake, and a giant geyser would be completely out of scale in a small town garden. For most purposes a medium-sized pump with a flow of some 2-3,000 litres (440-660 gallons) per hour is ample to give either a steady flow over a waterfall or a display of fountain jets.
The submersible pump works under water. It has a filter system that prevents fishes and pool debris from being sucked into the moving parts. The water is forced along a pipe to the outlet. Being under water it has to be completely sealed around the electrical circuit. The water keeps the pump cool, and it is silent in action.
The surface pump is usually much larger and more powerful, and requires a weatherproof pump house. It normally needs priming (filling the pump chamber with water to start the action), is often noisier and costs more. This type of pump is recommended only for very large pools where there is to be a spectacular water display, which is usually to the detriment of ornamental fishes in the pool.
Fountain nozzles are available in a variety of forms and can be fixed to free-standing figures, architectural mouldings or wall-mounted features such as lions’ heads or dolphins.