Purchased a new house with a pool in October '11 and it came with a large-ish ~20,000 gal pool, its irregularly shaped(kind of like a v shape) however and also goes from 3 feet to 10 feet at the deep end so the capacity is a guess. I called the local pool builder that has their name stamped in the steps and they said it must have been built before '95 because they have no record of it but only kept records from after then.
The pool looks great, I have no idea how old the plaster is but its not cracked or peeling or anything, and the water is crystal clear. I'm concerned about the chemistry first, as I'm assuming stuff like a replaster, I can worry about later as I'll just know when to do it because it'll start looking bad.
I purchased the standard 2006 Taylor chemistry set you all recommended and here's the #s for it after switching to bleach and acid for the past 4 months:
PH 7.4 (Tends to creep up after a week or two, I lower it with muriatic acid)
FC 10.5 ppm (prior owner was using stabilized pucks, I switched to bleach immediately)
CH 540 (!!)
CA off the charts, my guess is like 150-200
I live in Tucson AZ so the pool is not really “closed”, I'm still trying to tweak stuff to get the chemistry good over the winter. For the CYA and CH I know the solution is drain and refill, to try to keep things from getting ridiculously expensive I've been backwashing to right down to the bottom of the skimmer and refilling about once a week, but the numbers aren't really going down. Tucson water is EXTREMELY hard (the Taylor kit says my tap water is at 270) so I hope there's nothing more drastic I need to do. Any suggestions?