Author: Aqua Gardening

How to Select the Right Aquaponics Water Pump

Video Transcript:

Hi, I’m Chris from Aqua Gardening

In this Frequently Asked Questions Video for Thriving aquaponic gardens – we are going to look at how to select the right water pump for you. Water movement is vital for the plants, fish, and the whole operation of the system.

For the most basic and smallest systems, there are pumps which simply plumb into your pipe with an easy push, and will run your whole system. They use up from only 6 watts of power and have proven to be relatively reliable. See the link below to view our range.

Moving up to systems above 200 litres, the pond range of pumps is the most suitable. They all feature 10 metre power cables which is a great advantage outdoors. On the budget end of the scale are pre-filter pond pumps, that are low on power and come with a variety of fittings. Each has a small pre filter gauze which is necessary to protect the pump impellor from soft debris. It provides some bio filtration, and will require cleaning depending on the number and size of the fish in the system.

For systems above 500 litres of water, there is a range of dirty water pond pumps. These pumps may be 240V, 24 volt or solar powered, and can pump soft debris of up to 8mm in size. They will never require maintenance or cleaning, and are suitable for years and years of continuous operation. These dirty water pond pumps typically come with a pre filter cage containing no gauze, which is there to protect the impellor from hard objects such as leaves and twigs. These are our most popular pumps for aquaponics systems due to their feature of low power and high reliability.

To calculate the pump size you need it to suit the larger of these two requirements. The first, calculate the water volume of your system, and aim to pump this volume through your pump at least twice an hour. You can use our pond volume calculator to do this – see the link below.

The second requirement relates to grow beds. If you’re using media grow beds, you will need each flood and drain cycle to take around 15 minutes.

Calculate the water volume to pump based on 50% of the grow bed volume if you are using a timer to flood the bed.

We recommend the larger of these two sizes to be your pump size. Bear in mind, there will always be flow losses of water in the pipes, so consider using anti kink piping to reduce the number of elbows you will need. You should also take into account the height of the water outlet above the water level where the pump is located. The effectiveness of the pump reduces the higher it gets.

If you’re using an Aqua Gardening bell siphon for drainage, the siphon requires 400 litres per hour of water to run correctly.

This is a very versatile siphon, which has evolved over years of testing. As an example for the pump size, consider you have 2 grow beds with siphons, located 1m above the water level in the tank where the pump sits. To run the system, you will need at least 2 times the 400 litres per hour of water, or 800 litres per hour, pumped up to 1 metre head height. Shop for a pump that meets these requirements, and we always recommend selecting a pump that can do at least 30% more to allow for the length of pipe and bends to get to the outlets.

So a 2500 litre per hour pump will be the safest choice for this system.

Sizing your pump to these rules of thumb will ensure the system gets adequate water turnover while providing enough moisture and aeration to the plants. If you think you may expand your system, it is wise to shop for a bigger pump – you can always turn the volume down if required.

At Aqua Gardening, we are Australia’s leading experts in Aquaponics! Watch on to see more frequently asked questions we receive about aquaponics, or follow the link below to see how you can get access to our exclusive members only online video training and knowledge database – not offered by anyone else in Australia! I’m Chris from Aqua Gardening, and thanks for watching.