Need help with Hydro power project

[Azndude51]

I'm making a water wheel that will turn a motor which will generate power for an LED. I know how to measure power output by measuring the voltage and current. How do I measure power input? I have a flow meter to get the gal/min, but how can I get power calculated from that, is there something else needed?

Thanks in advance

 

[BrownTown]

potential energy is of course mass*gravity*height, so power would be dividing this by time. Your flow rate gives you gallons per minutes, use the density of water to get mass(kg), divide by 60 to get seconds, multiply by gravitational constant and by the height the water is falling and that will give you power output in watts.