Pentair IntelliFlo VSF Recommendations

Just installed yesterday as my 1 HP WhisperFlo finally died after 14 years. I'm new to the VSF pump but it doesn't seem so complicated after a few hours of playing with it yesterday. I live in Northern California so we get get 5 to 6 months of full sun everyday in late spring and summer months. I have a 15k gallon in ground gunite pool. I use liquid chlorine for sanitation. It doesn't get much traffic anymore since my kids are older now and have other interests. But we do use it during big gatherings a few times in the summer and a few days here and there with my family. There are no trees close to the pool so there isn't much debris that falls in it. Pool pump is located about 40' away from the pool at the same elevation. I do have a solar heater located on the 2nd floor rooftop and after playing with RPM settings yesterday, I found the sweet spot to work with the solar heater at 2800 RPM (1137 watts) no bubbles. I plan to run it at this setting during summer months to heat up the pool.

Now, if you have a better suggestion on how I can minimize my electricity bill while using the solar heater, please suggest. As for non swimming season months, I plan to set the pump at minimum. I'm thinking of running it at night for 10 hours. Maybe even 12 hours. To set to minimum RPM for this, should I just look at the skimmer to make sure it is turning? If there is a better way to test this, please suggest.

P.S. I had the Polaris PB4SQ booster pump installed as well as the old one died years ago. It is connected to a mechanical timer and I'm afraid to use this setup in case there is power outage. In the past, the mechanical timer turned on at unscheduled time due to the power outage and I was out of town. The booster pump ran with the pool pump off. It seems the only way to protect the booster pump is install a timer that will keep the time accurate in case of power outage. Any other ideas?