Heliocol solar panels flow rate?

[willymec]

I just replaced the 20 plus year leaking bad Heliocol panels. Replaced all 20 panels. 4x12.
They are on side of mountain direct sunlight.
I have intelliflo vs-3050 pump and use aqualink to control the actuator. Have installed a flow meter at the return to pool. Have installed adjustable valves on output and return pipes.
Getting 50gpm on the meter. Pump full speed 3450 rpms.
What would be the optimal flow rate? And how do i change it properly?

 

[willymec]

Also have a problem i cant seem to fix.
Only when the solar panel actuator is activated and it flows thru the solar panels. No pressure at switch
I have the caretaker 99 ultraflex infloor system. Only way to get the pressure switch to show pressure is when i just clean filters. Then a week later no pressure.
Or
Switch solar actuator to stop solar panel flow.

Replaced the pressure switch, i know it works fine after filter cleaning, but short lived or with solar off. I have the vs pump at 3450.