How to Calculate Feet of Head...???

[mas985]

From your pictures, it looks like you have separate runs for suction and return which means you will have 1/3 of the total flow in each run. This is a good thing for 1.5" piping which is pretty small. So three runs of 1.5" pipe is close to the same loss as 1 run of 2.5" pipe.

Given that you are running your pump, what is the filter PSI? Multiply this by 2.31 to get return head. Suction head you can estimate from the web site and it should be fairly accurate. However, my guess is you probably have about 10' of suction head give the pool configuration.

Also, the 42 GPM is the maximum "suggested" flow rate for a single pipe and probably not what you may actually have. To get the flow rate, you must determine the head of your plumbing and look up the flow rate from your pump curves. This value could be well over 42 GPM. But since you have three pipes, you can go much higher.