Your TA is fine at 100. Also, in a vinyl pool you don't need to be adding calcium. That is just another thing pool stores tell you to try and increase their sales! Keep an eye on your ph, though. You don't want it any higher than 7.8. Also, don't retest or readd any more cya for at least a week to be sure you have given it plenty of time to dissolve fully. Otherwise, you can end up with more in there than you want and the only way to lower it is to do a partial drain.