Executive summary: Increasing bubbles in return as flow rate decreases below 35GPM while solar panels are active.
Over the past 2-3 weeks, I've noticed increasing bubbles in the return while water is routed through my solar panels. To eliminate one possibility, I turned off my SWG which typically made some small bubbles and it had no impact. I suspect there may be a leak somewhere along the solar panel lines on the roof of my 2-story house, but would expect to see water dripping out too which has not yet been seen. The sudden increase in bubbles is so great that my Polaris crawler floats to the top of the pool and becomes useless. To get the bottom of my pool cleaned up quicker, I turned off my solar panels and increased my flow rate from 28GPM to 38GPM. Once mostly clean, I went ahead and turned on the solar panels only to find everything appearing to run normally again without any bubbles! Given my engineering background, I wanted to determine what flow rate was needed to avoid bubbles. It turned out that flows at or above 36GPM were bubble-free while bubbles clearly appeared at 35GPM and increased as the flow rate decreases. I would have actually expected the opposite prior to this experiment.
Does anyone have suggestions as to what the problem may be or how to debug further?