Safe to swim Chlorine levels

After reading another thread here, I have a question about chlorine levels and when it is safe to swim. Is it true that as your CYA levels rise, the higher chlorine levels required for sanitation of the pool rises, too?? And if that is the case, does the higher CYA levels protect you from the high levels of chlorine?? For example, the best quess chart says with CYA at 0-10, chlorine levels should be low, like 1-3 ppm. But with CYA at 100 or even higher, the chlorine levels required their are substantially higher. Are the chlorine levels equivalent between the two extremes?

I ask because a friend just bought a new house with an in ground pool. I went over to test his water, and the CYA was WAY over 100 ( I would say 200-300 but with my kit, the first line on the side with the black dot starts at 100 and it was well below that). I tested with my taylor 2006c kit. There was 0 Chlorine, also. I told him to drop everything and go get some chlorine, or else he would have a GIANT mess cleaning up the impending algae bloom. He has young kids who want to swim, so I want to make sure that keeping his chlorine levels at 10 ppm or so with that high CYA will be ok. The pool store guy says it would be unsafe, but I told my freind that is not true, especially with those CYA levels.

Here's the ultimate answer: dermatologists use (and have used for years) "bleach baths" (Google for it!) to treat a variety of skin problems in both adult and PEDIATRIC patients. The "bleach bath" protocol involves whole body immersion in lukewarm water with 50 - 100 ppm chlorine (from bleach) and ZERO stabilizer.

Now, I'm not recommending 50 ppm FC even for your friend with CYA=250 . . . but not because it's dangerous; he just doesn't need it!

And FC=50ppm + CYA=0ppm *will* damage swimwear. It might damage swimwear with CYA=250, though the evidence seems to be against it.

But FC=10 ppm with CYA=250 ppm is NOT a risk for your friends kids.