I can vouch for the effectiveness of running a fountain or other aeration device at night. On the advice of a friend, I began running the pump at night from mid-July until around Labor Day of last year. The aeration from the overflow waterfall from the spa to the pool provided enough of a cooling effect to lower the water temp about 4-5 degrees - not a lot, but noticeable. Plus, some electric utilities offer off-peak rates. That might be worth checking into in your area.
I have recently started this process again this year. As previous posters stated, pH and TA are relatively easy to manage.