Question 1

How do I size a pump for a hydroponic system?

Accepted Answer

Match pump flow rate to your system volume × desired turnover rate per hour, then add a correction for head height. For NFT, aim for 2× turnover per hour; for DWC, 1× is sufficient. This calculator combines all those factors and adds a 30% safety margin for the recommended figure.

Question 2

What is head height and why does it affect pump choice?

Accepted Answer

Head height is the vertical distance the pump must push water — from the pump outlet up to the highest point in the system. Every additional metre of head reduces a pump's effective flow rate. Always check the pump's head-vs-flow curve and size for the actual operating head, not just the maximum.

Question 3

How many times per hour should a hydroponic system turn over?

Accepted Answer

NFT channels need 1–2 turnovers per hour to maintain a thin film flow. DWC systems need 1× per hour to oxygenate the reservoir. Ebb-and-flow systems flood on a timer rather than continuous flow. For drip systems, the turnover rate is determined by the drip schedule, not continuous pump operation.

Pump Sizing

Pump Sizing