I think you should not use anymore cal-hypo for shocking. It's more expensive to use than liquid chlorine and your Calcium is already at 250, which is unneccessary for a vinyl liner.
Your CC is increasing because the chlorine, as it's consumed by whatever organics are in your water, becomes CC. As odd as it sounds, you need more chlorine to then oxidize the CC. It takes lots of chlorine, and POP - pool owner patience, when you have a situation like yours. You need to keep adding chlorine, sometimes several times a day, doing your best to keep the FC up to shock level, which can mean frequent if not hourly (in some extreme cases) additions of chlorine.
So more chlorine, and more POP....
Sorry, I know how frustrating this is... I really do.
Your CC is increasing because the chlorine, as it's consumed by whatever organics are in your water, becomes CC. As odd as it sounds, you need more chlorine to then oxidize the CC. It takes lots of chlorine, and POP - pool owner patience, when you have a situation like yours. You need to keep adding chlorine, sometimes several times a day, doing your best to keep the FC up to shock level, which can mean frequent if not hourly (in some extreme cases) additions of chlorine.
So more chlorine, and more POP....
Sorry, I know how frustrating this is... I really do.