I'm pretty sure that Ca should be 200-400 for your pool, but I'm sure someone will correct me if I'm wrong. I gather you're not swimming--I usually cut my pump runtime to 3-4 hours a day during thexwinter, and run it overnite if air temps are supposed to be 29 or lower (only happens a handfull of times during La winters, thankfully!!). Do you plan to close the pool or keep it open for the winter?

Janet