Quote Originally Posted by Pappy View Post
Do I really need a trash bag? I presume I run the pump into a container for 15 seconds, then weigh the water, multiply by 4 and divide by 8.34 to get the GPM?
I was assuming you had a submerged inlet. If you are able to plug the pool and disconnect the pump effluent, so you can discharge directly into your tank, you can get the measurement as you say.

Regarding the meter, with resistance elements VxA = true watts, but with inductive elements (motor windings), true watts are usually less than V x A due to power factor.