We added some Ca hardness from the pool store to a spa. After 2 weeks, it just sat in the pool completely undissolved. It also managed to get into every filter, jet, etc. The spa has been just emptied and refilled... is there something we are doing wrong in the addition of Ca hardness? Is there a better way to do it, or do I need a different form of the chemical from the store?
(It's little round spheres, almost perfectly round, about 1/8 of an inch in diameter, white in color.) It's the same chemical as the spa version, but I'm wondering if the spa version is generally in smaller pieces, and hence dissolves more easily.