How is powerhead flow calculated?

[Krampus]

It’s easy to calculate the flow of a return pump. It’s dealing with a confined tube or pipe to push water through and can be easily measured or calculated. However, how do they figure out the flow rates for powerheads? Take a gyre, for instance. It has such a wide area of flow, or a sine style powerhead that pushes a very wide spray. How exactly are they calculating these flow rates?

 

[Dan_P]

It’s easy to calculate the flow of a return pump. It’s dealing with a confined tube or pipe to push water through and can be easily measured or calculated. However, how do they figure out the flow rates for powerheads? Take a gyre, for instance. It has such a wide area of flow, or a sine style powerhead that pushes a very wide spray. How exactly are they calculating these flow rates?

Isn’t flow rate measured?