Tested 2 samples:
City water: used to fill the pool when it runs low:
FC - 1.5
TC - 2.0 (CC was 0.5)
TA - 450
CH - 20
CYA - 0
PH - 8.2+
FC - 25 (!!)
TC - 25 (CC was zero)
TA - 300
CH - 300 (Lesson here - if you don't watch this one carefully, it'll go from blue to clear and you'll miss it)
CYA - 100+
PH - 7.8
The pool is a 12K gal IG pool with DE filter. Never gives me trouble. Crystal clear water, no cloudiness, no algae; I only add chlorine tabs to diffuser when it runs low. Thanks to this website, I have returned all "extra" chemicals to the pool store and now I have only two items in my storage bin - chlorine tabs (just bought a bucket - darn) and DE. Tabs go into a simple chlorine diffuser downstream of the filter with an adjustable dial to control dissolution of the tablets.
My guesses (which I want feedback on):
1) Drain the pool in 25% steps to lower CYA. This will also lower the FC to more appropriate levels. Refill pool and retest CYA and FC.
2) Add about 12 oz of muriatic acid to lower PH to about 7.5. And, it looks like I need to keep muriatic acid handy to deal with the high-PH city water when I add water to the pool.
1) What are acceptable levels of FC? The OT test vial ranges from 0 to 5, so it 2.5 the target?
2) What do I do about the high TA of the city water? Does acid take care of this?
3) Anything else?