I'll chime in here with my recent experience. High CYA, about 220 to 240, full sun, 100+ degree weather, PebbleTec finish. Completed a successful half drain a few weeks ago and had to babysit the walls as they dried out. Now CYA is at 120, still high, but manageable until fall when I can take it down halfway again. We did a slow drain (per local water company preference) and a comparatively fast refill. Went smoothly and other than having to babysit the pool, it was actually nice. Just my recent experience. Yours may vary..