Water Flow Rate in Aquaponics

The rate at which your water is flowing through your Aquaponic system is crucial to the health and well-being of your system. You want to make sure you are cycling your water often enough to keep the fish healthy but not too often that your operational costs fly through the roof. Let’s walk through the water flow rate in Aquaponics.

We can use the water flow rate back into the fish tanks to determine how often the water is changed per hour. Before we go any further, it’s important to know how often your water should be changed over and this depends on the type of fish you are farming. For example, if you are farming Tilapia then you should have your water change over every two hours. Moreover, it is important to note that you should change the entire volume of your fish tank through your grow beds every hour if you are at maximum stocking density.

Our biggest tip when it comes to designing your system is to rely on physics. Try to design your system to optimize the use of gravity to flow your water through your aquaponics system. You can easily design an aquaponics system on flat ground while only needing a pump to return the water from your DWC back to the fish tanks. The rest can be done through the strategic placement of elbows and the use of gravity.

This is as easy as taking the volume of your fish tank and calculating how many litres you would like to turn over in 1 hour. For example, if you need to change over the total volume of your fish tank every 2 hours. Then you can take the total volume of your fish tank and divide it by 2 to get the flow rate in litres per hour format.

Friendly Tip: Sometimes it may help to calculate the flow rate of your media beds and DWC to see if it exceeds the flow rate of your tank turnover. This is usually quite rare but here’s a video to help you out.

Yes, let’s say you were able to use gravity to get the water to flow down to the DWC without the use of a pump. However, now you need to return that water up to the fish tanks. This height between the level of your DWC and the level of your fish tank is called the head height. This is the height that you have to overcome when pumping the water back into the fish tank. Therefore, this calculation is crucial as the flow rate of a pump decreases when pumping water upwards. Then you’ll need to use the pump curve to see the actual flow rate your pump can provide while taking the head height into account.

Friendly Tip: Try to design your system so that the head height is as minimal as possible. As this saves the amount of electricity required and therefore, saves you some cash.

You can use the calculation below to help you decide on the size of the pump required. Make sure to check out our range of Jebao Pumps available in our store. We have put our trust in these pumps for years and couldn’t recommend a more reliable pump for your system.

Pump Size = Total Tank Volume (m³)/ No. Water Changes per hour

Remember to take a look at the pump curve to make sure your pump suits your actual flow rate.

Make sure to do your calculation to ensure that you are at the optimal flow rate without breaking the bank! We hope this post gave you some insight into calculating the water flow rate in your aquaponic system. If you are unsure, feel free to contact us with any queries.