Quote Originally Posted by keithw View Post
Gonna give it one more shot though.
When you do the drain and refill, there will still be residual CYA in the pipes and stuck to the walls that you can't get rid of so just be aware that there will still be a small amount (probably < 5 ppm, perhaps only 1 ppm though you can try testing for it to see). I suggest you not add salt to see if that makes any difference. Notice that you have a large FC now, but also have CC which makes me think that indeed there is something consuming a lot of chlorine in your tub.

I'm keeping my fingers crossed that the chlorine will hold this time, at least after some initial use. Keep us posted.

Richard