My thinking was that since Hayward pairs the 18" filter with the single speed 1 HP pump and a 1.5 HP 2 speed pump as complete systems - I couldn't be going too far wrong with a 1 HP 2 speed pump. If it needs throttled to backwash on high without flushing sand out - so be it. The only way I see this is a bad deal is if the pump doesn't provide enough circulation on low, and I don't think that's likely. As far as the valves go, I hadn't realized one was "pool rated" and the other "industrial".