Maybe I didn't look in the right places or use the correct search words but I couldn't find info on CH and what the level should be for a vinyl liner. I checked mine today and got a reading of 30. I keep our pool open all year and figured since the weather was getting nicer that I needed to get on top of the chemicals a little tighter now. I never really thought much of the CH since I want to say I read on here that it isn't really important for a vinyl pool but wanted to make sure since reading my test kit manual stated that it should be between 200 and 300.
Salt level = 3000
PH = 7.3
TA = 80
FC = 5
CH = 30
CYA = 20, I'm slowly raising it back up to 70.
24,000 gallon IG with vinyl liner that was just replaced in 2011 which is when the SWG was added. Also using a Pentar Quad 4 DE filter.