I have vinyl and have read feed shock in skimmer or predissolve and add, the shock I have(AquaChem "SHOCK") from WalMart says do not predissolve, apply in dry form thru skimmer or directly to pool and brush tilldissolved(not preferrable). Are there any advantages or disadvantages to each.
I have also been unsuccessful at reducing the CC in the pool, I normally use the BBB method and am conservative on the additions I make at one time but may not be adding enough bleach to do the shock level. I had FC=1, CC=1.5 and added 2 of the 96 ounce container which was probably not enough. The pool calc was a bit more. CYA was 0 but added some recently to bring it up