Is it normal for some CYA to degrade over winter? Is there any reason to want your CYA to be at the top end of your range when you close your pool? I am asking because right now, my CYA is a little under 30 (had to drain some water a few times because of excessive rain). I am not having problems keeping my chlorine up because I am using my solar cover all the time unless I am in the pool now that the nights are so cool. So, unless its a good idea to bump it up for winter, I was just going to leave it as is. Thanks in advance for the advice!