It sounds as though the pool is not complete so you cannot measure it. With an existing pool you can measure existing head via the filter PSI and pump vacuum. However, you will need a vacuum gauge which you can get at Sears or OSH in the auto hardware section.
Some builders use 50' or 60' of head as a standard pool build but depending on the design, this can be way off. Also, most pool builders do not have the ability to do a head calc. You could hire a hydraulics engineer to perform one but it will be expensive. They also don't tell you that head is dependent on the flow rate through the pipes and the pump flow rate is dependent on the head. This is a circular calculation which requires an interative solution.
Also, the exact calculation is quite complicated and requires detailed knowledge of all the pipe size & lengths plus all of the fittings and equipment losses. If you are up for it there are some good references to get into the details but it does have a steep learning curve. I have detailed spreadsheets which do the calculations but again, the inputs need to be pretty accurate.
This approach may be best suited for your situation:
http://www.poolplaza.com/pool-pump-sizing-2.shtml
http://www.poolspa.com/publications/...ries/pumps.htm
Bookmarks