<a href=showthread.php?s=&postid=10467000#post10467000 target=_blank>Originally posted</a> by an411
The reason I am asking this is I want to get everything running perfect or I should say efficiently
Honestly, you don't really need to know the flow rate in order to optimize it, since it's already common knowledge as far as what is restrictive to flow.
Firstly, make sure you're using the correct pipe sizes for your pump. It should come with a spec to tell you what diameter to use for the input and output. Keep in mind that if you split the output, you can't always bump down to a smaller pipe size, as some people tend to do. The critical measurements are the cross-section of the pipe and the surface area of the wall inside it. Cutting the diameter of the plumbing in half is equivalent to
quartering the cross section. The simple way to think of this is that two 1/2" pipes are MUCH smaller than one 1" pipe. So if you split the output, keep the pipe size the same - unless you split it many, many times.
The other critical item is bends and turns in the piping. A 90 deg. bend is your worst enemy! Unfortunately, many people plumb several of them into their return piping. Instead, consider using two 45's right next to each other, which is less restrictive. Also, plan the plumbing beforehand to require as few bends as possible.
Do those things and your system will be optimized, regardless of whether or not you actually know the flow rate. Though, measuring it would definitely be a really fun experiment.