Water pump selection for water features

Pondkeeper's How to...

Water pump selection made easy

Water pump confusion removed ... you will hear terms like maximum head, maximum flow and pressure drop when people talk of water pump selection for ponds and water features. We help you out here

Your water pump .... Important requirements when a water pump is used in conjunction with water features are briefly discussed below. In any pond, fountain or water feature it is generally necessary to install a water pump to achieve the following ...

A water pump provides oxygen for fish ... the water pump in circulating the water over a waterfall or through a spray or a drop from one level to another allows oxygen to become dissolved in the circulating water.

A water pump provides oxygen not just for the wellbeing of the fish but also to maintain suitable conditions for biofilter bacteria. The water pump used in fish ponds must run 24 hours per day otherwise those beneficial bacteria in your biofilter will die from oxygen starvation. Removing waste chemicals secreted by fish in a water environment needs lot of oxygen which must be dissolved in the water.

Water pump ... selection introduction

The points briefly discussed here are considered in far greater detail by following the pond water pump links on this page. This what you need to look for and learn a bit about ... your dealer may not know much more than you so beware

A water pump of the type we will discuss is used extensively in all types of water features. Such a water pump is referred to as a centrifugal water pump ... quite simply this means the pump has an impellor that spins around and use centrifugal force to deliver water. They are low in cost to manufacture and hard to damage because even if the outlet from the water pump becomes blocked no damage occurs. In this way flow control is made easy by restricting the outlet pipe using a valve or even by clamping the pipe partly shut.

Using a water pump in ponds means using a submersible water pump in something like 99% of all circumstances ... the pump wopuld normally lie just off the bottom of the pond, completely submersed. Because they are submersed the height a water pump needs to pump against is measured from the water surface and not from the bottom of the pond. This height is normally referred to as "head" in water pump jargon.

Think of a water pump as being able to provide a fixed amount of energy to circulating water. Think of this constant energy derived from the electric motor as being shared out in 2 ways .... water pump energy in part 1 is used to pump volume and the water pump energy part 2 is used to lift that volume. If you give larger share of this energy to volume then the lift has to be less

Here's a simple analogy .. you would need the same energy if you carried one bucket of water up a flight of stairs 20 feet high as you would if you carried 2 buckets of water up a flight of stairs 10 feet high. A water pump is just like this ... if you want to pump more volume higher then get a bigger pump. One size cannot fit all situations for the simple reason the energy from the pump motor is constant in most cases.

You will now understand that to specify and buy a water pump that will do a good job it is necessary to know how much water is to be pumped and how high that volume of water must be pumped. Without both bits of information you cannot specify a water pump accurately.

Now if you want to really explore this further follow the water pump links on this page ... but one word of warning here. If you see words like maximum head and maximum volume stated for a water pump these terms have little practical significance and buying on this basis will lead to disappointment and wasted money.