Bleach not staying in pool?

[waterbear]

Evan, So it's probably not bromine, right? It would be showing up on the tests at a much higher level if it was there, wouldn't it? (Excuse my ignorance if I'm misreading your post.)
Not unless the tester is also calibrated for bromine readings and you use that scale!
If it was ammonia based, wouldn't it already have been consumed by the relatively high doses of chlorine he's been using?
maybe, maybe not...depend on how much is there and how much chlorine has been added.
You may, of course, yet be right (as you usually are), but I'm guessing Dave was on to something with his lurking organic theory.
one of the organics in the water is possibly ammonia or urea...same effect as adding a non organic form of ammonia...creates a huge clorine demand. either way chlorine is the answer.
Waterman, I don't think anyone is saying that the Yellow Out, whether bromine or ammonia based, is falsely supressing your chlorine test readings. Rather something is consuming your chlorine.

Read the 2nd of Ben's articles that Evan linked to; it should answer your question on getting the bromine out.

As to what you should do, absent some other revalation, I think going back to the basics of keeping your chlorine at shock levels, until it holds over night, is your best bet. According to Ben's Best Guess chart, for a CYA level of 60-70, that would be 20 ppm (http://www.poolforum.com/pf2/showthread.php?t=365)

Best of luck.

Hope this is helpful!
Perhaps Ben will add his expert knowledge to this thread. I've reached the extent of my limited knowledge!

Edit: just reread the posts and noticed that h2Oman is keeping the pool covered. Don't know if that is part of the problem but it might be.