Looking for some help in figuring out how to size a pump for a custom slide. The slide has dual 1" inlets and requires a total of 80 GPM. I will have a dedicated pump for this slide. Dedicated drains, 3" plumbing from pool to pump and from pump to slide (in case I use a different slide later that needs more water). It will split into two 1" feeds at the slide. Manufacturer recommends a valve on each feed to adjust flow.

Question is, one PB is quoting a 2hp, single speed pump. Looking at the flow charts, and estimating TDH around 30-40?, it seems like this pump will push over 150 gpm!!! That seems like way too much!

How can I properly estimate TDH and get the proper sized single speed pump? And, silly question, but if I got a bugger pump than needed, and adjusted the valves at the slide to limit flow, does that have a negative impact on the motor?