Thanks. The ph was 7.4. I guess I'll have to shock next week. (I want to use the pool this weekend. When you mention holding the chlorine overnight, do you mean absolutely? Like if I check it at 11:00 pm and it's 15.2, then it should be 15.2 at 6:00 am? Also, how do I lower the calcium? Will it affect anything else? Thanks for your help.

Tisha