04.Choosing and installing a pump
What to look for in a pump
- Discuss your particular needs with an expert, such as a speciality tank and pump supplier. They should be able to recommend a tank and pump to suit you.
- Pumps that turn on and off automatically when you turn on the tap (or hose) are easiest to use. You’ll need a pump of this type if you connect it to indoor plumbing. Other pumps must be switched on or off manually, which is easy to do, but can be inconvenient.
- Multiple outlets on the pump allow you to run more than one hose, or a hose plus a plumbed-in connection.
- Run-dry protection prevents motor damage if the rainwater tank is empty.
- Submersible pumps are generally quieter than external pumps, as the water in the tank muffles their noise.
- A carry handle is useful if you need to move the pump between different sites, but isn’t necessary for permanent installations.
Installing a pump
None of the pumps in this test came with the necessary fittings and hose to connect them to a water tank. You have to buy those separately. The supplier should be able to recommend the right fittings.
You’ll need a weatherproof power point for the pump. If there’s none close to its location, have one installed by an electrician. Don’t connect the pump via an extension cord to an indoor power point, as this might not be weatherproof and could be unsafe.
All the pumps in this test are easy to install. For the external pumps, you just connect the pump inlet to the rainwater tank using a short piece of kink-resistant hose, secured with two hose clamps. The distance between tank and pump should be as short as possible. Next, prime the pump with water, plug the pump into the power and switch it on. Then connect a hose to the outlet and you’re ready to start watering.
For the submersible pumps, connect the outlet to your garden hose, then lower the pump into the tank (the Onga Dominator came with a length of rope for this purpose) and plug it into the power supply. Don’t use the power cord to lower or raise the pump.
Ideally, you should put a housing or cover over an external pump to protect it from the weather and muffle its noise. Most of the pumps in this test are about as noisy as a loud vacuum cleaner, and some have a high-pitched whirr that could be annoying.