Solar heating 2 different head sizes

[SpacemanSpiff]

Hi all, so I bought used some solar panels, ones with 2" and 1 1/2 head. I would like to install all of them... I have a few ideas but not sure... Thoughts on
Install of 2 different sizes heads?

Hot Sun Solar Pool Heating l How Does a Solar Pool Heater Function?

Detailed plumbing and operating instructions of solar swimming pool heaters.

www.h2otsun.com

Thought about installing the way the last diagram shows (adding in another bank) where the top bank is 2" and the lower back is 1 1/2

 

[jblizzle]

I would think you would want to run through the 2" headers first and then the smaller ones. Although if the banks are in parallel it likely does not make any difference.

That bottom picture is fine, although usually you do not need all the isolation valves that they are showing.