Run Solar While SLAMing?

[tstack22]

Do I need to leave my solar heater on while SLAMing, or once I have the tubes filled with high FC water can I turn it off?

 

[ajw22]

I would turn it off.

I thought the tubes in solar panels drain when off.

 

[tstack22]

I think they're supposed to, but mine looks like a DIY job. It's just 800' of black poly tubing in coils on the roof.