Sungrabber solar panel flow rate calculation

[CarlD]

Doesn't sound high to me. I have a Hayward 1 hp Superpump 2 spd and 20lbs is perfectly normal for 8 years now. When it hits 25 lbs I have to backwash. Since my solar panels are on a "Y" connection with the return, I don't see much of a change in pressure when they are on. My pump is only about 5' from the pool, and my return line is maybe 10' long and rises no more than 4' above the pump, plus another foot to the solar panels. I have 240 sq feet of panels.

[mas985]

The reason I think it is high is because 20 PSI is about 49' of return head (adjusted for filter gauge height of 3') and if you assume another 5' of suction head, which is probably on the low side, results in 54' of total head loss. That pump puts out about 34 GPM @ 54' of head so the plumbing would be the equivalent of almost 800' of 1.5" pipe! To me it seems like a lot of head loss for such little flow rate. Also, the operating point is on the far left of the head curve which is far from optimum. If true, then there is something in the plumbing which is causing a lot of heat loss.