I bought a house with a pool 2 months ago, and I've been diving into pool maintenance. I live in the Bay Area with max summer temperatures typically around 80F.
When we moved into the house, the pump was set to run at only 3-4 hours per day, and the booster pump at 2 hours. I initially neglected adding any chlorine, but for a full month, there were no adverse effects. The water stayed crystal clear. I bought a chemical tester, and the chlorine slowly dropped to 0.8ppm. At that point, at the end of the day, I get brownish/black stains at specific locations of the pool. They look at bit like a comet and its tail. In the morning, those stains are usually gone again. Not sure what those are. (Black algae?)
Anyway, after a visit to Leslie's, I did a pool shock, and I'm now running the pump at 8 hours and the booster at 3 hours.
We just got our first electricity bill, and it's quite a whopper at $270. After a deep dive, it's obvious that the pool is responsible for 80% of that. (We don't have airco.)
My question is: is it really necessary to run the pumps for this long?
I assume I can reduce the booster pump running time from 3 to, say, 1.5 hours as long as everything stays nice and clean?
What about the main pump? Why does it have to run for so long? As I understand it, chlorine level is what keeps algae away. So what's the primary usage of the filter? Is it just to remove small debris? What am I missing?