I should add, you CAN swim at all those levels . . . safely.

Bleach baths at 50 - 100 ppm chlorine with NO CYA are recommended every day by dermatologists, even for pediatric eczema.

But, swimwear is more sensitive to chlorine than skin, so if you have to take levels above 30 ppm, wear old swimsuits!

Keep in mind, that with CYA = 200+ your EFFECTIVE chlorine levels are far, far lower than the indicated levels.

One more thing: the very high CYA levels will mean you can probably add chlorine as little as 1x per week, instead of daily.