Solar Panel plumbing and flow rate

[Slachey]

The filter pressure is ~ 20 psi either through the panels or not.

[mas985]

20 PSI is about 46' of head but only on the return side. Suction side is probably at least 5' of head. That is 51' of head and according to the head curve, you have about 25 GPM so not much flow rate at all. But the head loss in your plumbing is extremely high for the given flow rate (~5x the average pool with 1.5" plumbing). So I suspect there is some issue with the filter or other parts of the plumbing.

Is 20 PSI the clean pressure and has it always been that high?

Have you backwashed/cleaned the filter recently?

[Slachey]

When you say "issue", I am not sure what you are referring to? Note that there is 50' of 1.5" flex PVC going to the panels and 50' of 1.5" flex PVC coming from the panels. The 20 psi is typical, even after backwashing. The flow from at the pool return is very strong, and when I backwash, flow is quite strong as well. I just turned the pump on and checked the pressure gauge prior to starting. It was at 0 PSI.

[mas985]

What I mean by issue is that your pump is a low head pump and 20 PSI is awfully high for a pump like that so something in your plumbing is causing a lot of head loss.

But is the water traveling through the 50' of pipe without solar engaged as well?

[Slachey]

No. As explained in a previous post, I have an horizontal "H" manifold which is located next to the pump, although there is a 8' hose connecting the filter to the rigid manifold.

[mas985]

Maybe a picture of your equipment would help me understand the layout a little better.

[Slachey]

I cant simply upload photos, as the link is asking me for a URL address?