Pond Equipment » Pump Energy Discussion

After building a koi pond, the biggest expense will be the cost of electricity to operate the pump. For that reason it is important to make plans right from the beginning stages as to how to keep the electrical use to a minimum.

Things to consider in planning your pond

1) The pond pump will need to operate 24 hours a day to provide oxygen for both the koi and the beneficial bacteria in the filter. The bacteria in the filter that removes the ammonia and the nitrites from the water is aerobic bacteria which means that it needs oxygen to survive. If the pump is off for more than 4 hours at one time, this bacteria will begin to die off.

2) The way a koi pond is plumbed is extremely important when it comes to operating cost. If the pipe size used is too small or the plumbing has too many elbows in it, it will take much more power to move the proper amount of water through the system. This means you will need to add a larger pump to accomplish what you could do with a much smaller pump had the pond been plumber properly. See Advantage Koi Pond Design Plans.

3) The larger the pond is, the more electricity it will take to operate. For proper water quality, all the water in a pond must go through the filter a minimum of once every three hours. A 20,000 gallon pond is going to cost almost twice as much to operate as a 10,000 gallon pond.

4) A beautiful waterfall is an important part of a successful koi pond. There is a need to be careful in designing a waterfall. Building a waterfall that is too high (over 4 feet) or one that requires a large amount of water to “look good,” can greatly increase the pump size required to operate the pond.

Some things to consider when selecting a pump for your koi pond.

Most pumps used on koi ponds today are the low speed type pumps. They operate at 1725 rpm instead of the normal 3450 rpm. This low speed coupled with a larger impeller allows these pumps to very efficiently produce a relatively high flow of water and still operate very quietly. Their only short coming is that they do not produce much head pressure. Head pressure is a measurement in “feet of head” of the volume of water a pump can push straight up through a pipe, at a particular height.

As you can see from this flow chart, depending on the head pressure this pump could give you as much as 100 gpm or as little as 10 gpm depending on how much head pressure the ponds filter and plumbing produce. For that reason it is important to know both, how much head pressure you are dealing with and how much head pressure the pump you are considering will overcome at a specific water flow. Keep in mind also that as you increase the water flow in a system the heads pressure will increase also.

As you can see, estimating the head pressure and thus the performance of a particular pump can be complicated. For that reason we tested each of the Plug and Play Systems with not only their standard recommended pump but also with several optional pump combinations to show you exactly what you could expect. In addition to testing their water flow, we also tested their energy consumption at different head pressures. This makes it possible to accurately predict exactly how much it will cost to operate the complete filter system including ultraviolet light. For your particular pond you will need to estimate any added head pressure that your system might add after the filter, such as how high your waterfall is and how many jets you have. A modest 3 foot high waterfall and 3 jets might increase the head pressure by 6 feet. By looking on the performance chart for each Plug and Play System you can then accurately estimate the performance of each system.