Background - My wife and I bought a "new" house (circa 1966) with a 10-15 year old pool that had been on a constant puck diet. The CYA was north of 180, CH was well over 1000 and the rest was just jacked.
Fast forward a month (been considering a drain and fill - waiting for a weekend that wasnt precluded by a massive rainstorm). I've been keeping my eye on the chlorine and testing CYA after each rainstorm and what do you know: This morning I'm at a CYA of 45, PH 7.4, FC of 4, CH of 620 (still high but ...), TA of 120 and the pool is BEAUTIFUL.
Pictures to follow.