candy - you have gotten some good advice from these folks. Don't fear the higher CL levels required when your CYA is high. Without this higher level I would expect a green pool, so I too cannot offer an explanation as to why yours is clear. I agree that you need to get your CYA down (to reduce CL costs if nothing else) and there is no way to do this other than a water drain and replace. Try the dilution idea to get a good CYA level reading that you have confidence in, and if it is over about 60ppm, consider another water change. I would not drain more than 1/3 of your volume at one time, to avoid the possibility of "pool floating".

Also, stop using stabilized chlorine... it will just lead to a reoccurrence of this problem. Plain unscented bleach works great.

~Rick~