I have a 9,400 gallon plaster pool in Southern, AZ. My CYA is > 200 from using chlorine bricks (before discovering this site). Using the pool calculator, I need to drain approximately 80% of my pool. When doing a google search for properly draining a pool, just about every site says not to, or I run the risk of the hydrostatic pressure raising or popping my pool. This scares me quite a bit. What do I need to do to get this done safely? I'm sure I could pay the pool company to do it for me, and the liability rests with them, but what are they going to do or have that I couldn't?
The pool was built in 2004 by the previous owners, so I'm not sure if there's a hydrostatic release valve or not. I'm not even sure what to look for with this. The guy at the pool store said just to drain it and refill in the same day and I'd be fine, but given all the warnings online I'm a little hesitant. Does anyone else in this part of the country have experience draining a pool?