Quote Originally Posted by matthewnadeau View Post
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I meant to say that the free chlorine and combined chlorine have never read below 5ppm.

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Just wanted to clarify: Total chlorine = free chlorine + combined chlorine. The goal is to get your total and free chlorine equal, which would mean that your combined chlorine (the chloirine actively fighting something in the water) is zero.

I'm willing to bet that your CYA level is very, very high--which is probably why you're not losing much chlorine. If you keep your chlorine higher than 5 at all times, though, it looks like it'll work for your pool. Do you close this pool in the winter? If so, you might want to consider a partial drain/refill to lower your CYA levels before closing. If you have a bad algae bloom over the winter, while the pool is closed, it can break down the CYA into ammonia and create a HUGE chlorine demand when you start up again in the spring.

When you shock it, what are you shocking it with?

Janet