Thanks, everyone, for your thoughts. I am adding 50 ppm borates to the pool this weekend and will keep a close eye on things when I start using trichlor tabs next week. My goal is to minimize the amount of active maintenance my pool needs. Pool guy used to come once a week and add liquid chlorine best I can tell, but now that I know what is involved, I see things were certainly out of whack for part of the week as it doesn't really seem possible to maintain a pool with once-a-week maintenance.