High Chlorine Level

I opened my pool 3 weeks ago, and shock it as I normally do in the begining of the season. I took a sample to the pool store and my FC was 13, two weeks later it's still at 7 -8 PPM FC. I have an automatic chlorinator and it seems to be functioning properly. Is there a reason why I can't seem to lower the FC? I put in 3 pounds of chlorine nuetralizer which seemed to help lower it from 11 - 7. Any thoughts?

If you have an automatic chlorinator, I'm sure that's why it's sustaining a high level. Otherwise, there's no way a pool would hold that much chlorine for 2 weeks. What is your stabilizer level? With an auto chlorinator it can rise very high very quickly, so you might actually need to keep the chlorine at 7-8.

Janet