However large or small your koi pond is, you will need to incorporate a range of water pumps to keep it healthy! Water pumps are necessary in order to keep your filters working, and also to provide oxygenation to the depths of your pond, and keep the water moving.
The specific size of the pump you will need, and how many of them, will vary depending on both the size of your pond and its layout. Your pumps should allow for turnover of water throughout the entire pond with no dead spots, but they should not be so powerful that they disturb the substrate of your pond or make the water churn!
There are various different types of pumps available and we will explain the main types and their respective benefits below.
Feature pumps are generally small and intended to power a water feature such as a bubbling stream or a fountain. They are usually designed specifically for use with a surface level or above-water feature and will control the water movement within the top level of the pond or within a small area only.
Fountain or waterfall pumps
Fountain or waterfall pumps are sometimes referred to as combined general purpose pumps and may be used to operate a fountain or waterfall and a filter simultaneously. Generally, just one filter of this type will not be sufficient to serve the needs of your entire pond, as they will normally only provide power to the filter and water feature in one area of the pond.
Solar pond pumps are a great option for pumping the water within your pond if access to an electricity supply is difficult, as these pumps are powered by solar energy, as the name suggests!
However, they do of course rely on there being sufficient sunlight to keep them running, and you will generally need to install several within the pond to provide adequate water circulation if these will be your only means of pumping the water around.
All-in-one pumps are one of the easiest solutions for smaller koi ponds. They can also be used in larger ponds if you are able to set up more than one of them. Not only do they pump the water around the pond, but they also incorporate biological filtration and sometimes, a UV sterilizer too.
Choosing the right pump or pumps for your koi pond
You should base your choice of a pump on the requirements of your pond and your fish. You will almost certainly need to provide more than one pump, and possibly more than one type of pump to get things just right.
It is wise to take advice from a koi or pond building expert when choosing your pumps and make sure that your pumps have adequate power to circulate the water and feed your filters properly. Remember when you situate your pumps that they should be easily accessible for maintenance, and keep the pumps themselves a couple of inches off the floor of the pond.
Ensure that the water pushed out by the pump is diffused rather than coming out as a jet of water, in order to avoid damage to pond fittings and creating too strong a current for your fish.