Update: Pool is back to regular levels, so it's safe to run the pump cycle again. We turned it on, added a gallon of bleach and let it run for a while this morning. Then, on my way to work, I stopped by and got a few numbers.
pH: 7.2 (was 6.0)
TA: 120 (was 160)
CH: didn't test
FC: 14 (was 34)
CYA: GUESSING 90 - 100 - It was raining and pump hasn't been on long, so didn't test. Will test later today if sun comes out and pump cycle has run for a long while.
The pool has a green tint to it, but that could be a number of things, even the horrible quality of tap water here in Orange, TX. The FC count is decent, however, as a ratio of the CYA levels I guesimated, so I'm thinking it's nothing I should worry about at the moment, but I wanted your thoughts?
Also, bonus, while not the quickest solution, future pool drains of a small degree can be done by draining the Spa, since I don't think a 100% drain of it will hurt as long as I run the Pool mode, and not spa mode (so it doesn't use the Spa drains). That should empty 500 - 600 gallons at a time and a small sump pump should make quick work of that, then fill it back up in pool mode, and drain again to get a few thousand gallons over the course of a couple hours.
Oh, and other than the 1 gallon of bleach, I didn't add anything, but have my dad running the waterfall to aerate and also hopefully bring that 7.2 ph up. I didn't want to add borax, considering my information on the board suggests 7.2 + aeration can get me up without overshooting. Thoughts?