When using tank water for your home, you will need a water pump to deliver the water. There are two different types of pumps that you can install, and connect to your rainwater tank, they are a submersible pump or an external pump. In this article, we will explore the differences between these pumps to help make your decision easier.

What is a External Water Tank Pump

The most popular pump for rain water tanks is an external water pump. The external water pump is preferably positioned next to the rainwater tank, and should be protected from the weather with a pump cover. External pumps are also known as above ground pumps or surface domestic  pumps.

What is a Submersible Water Tank Pump

A submersible pump is positioned inside the tank and is designed to pump water vertically through the roof of the tank.

Pros and Cons

There are advantages and disadvantages for each pump. Here are a few things to consider when making your decision:

• Price – A submersible pump will generally be more expensive, as it has been designed with waterproof casing, so it can be placed inside the tank.
• Energy Efficiency – A submersible pump will be surrounded by water, so it will just need to focus on pumping water. An external pump will need to pump and suck water, which would in turn use more power.
• Noise - A submersible pump will be very quiet as it is surrounded by water. Water is great for absorbing noise. An external water pump will be much louder as it is placed outside the water tank.
• Maintenance and Accessibility – An external pump will be easier to maintain and service as it will have easy access. As a submersible pump will be located inside the tank, it will require some dismantling to access the pump.
• Waterproof Seals - Waterproof seals are required on submersible pumps. Over time they can corrode, allowing water to get into the motor. The seals must also be replaced after any inspection or repair.
• Tank Capacity – As a submersible pump will be placed inside the tank, it will result in less water being held inside the tank. Depending on the size of pump, it may be up to 50 litres less water.

We hope this article helps you decide between a submersible or external pump.