Air in pool lines when pumps first come on

[Mmark]

When pools starts every morning huge amounts of air come out for about 30 seconds. Also at night when pump is off, I can hear water trickling out of solar system into pool return pipes. No visable water is around pump lids or valves and lids do not have air in them in the morning. Pool is about 3 years old. And it seems more and more air comes out as time goes on

 

[jblizzle]

The solar panels are plumbed and designed to drain when the pump turns off, thus filling with air. When the pump and solar turn back on, all that air is pushed out of the solar panels and into the pool. Completely normal.