Unless your Calcium Hardnes (CH) is low, you shouldn't be using Cal-Hypo anyway. You didn't report your CH number -- do you have a good test kit such as the Taylor K-2006?

Cal-Hypo often has trouble dissolving well and can be pre-dissolved in a bucket of water first before adding it to the pool. However, it would probably be better for you to be using either chlorinating liquid or 6% unscented bleach instead.