Not having success with BBB in my hot tub

[chem geek]

A P.S. to my last post above.

I have been told that many State health departments are now saying that no form of stabilized chlorine should be used in a hot tub, so that is probably where you heard this. Also, I heard that HTH has recently discontinued their Di-Chlor packaged for hot tub use and now only sells Cal-Hypo as a spa chlorinator and spa shock.

So the conservative approach would be not to use any CYA at all in the hot tub. I would say that if you find you can keep your chlorine levels stable so that you don't run out or get to low levels too quickly, then that would be OK. The very high disinfecting chlorine levels when no CYA is present will certainly kill off virtually everything including hot tub itch bacteria rather quickly, but will also fade (and degrade any rubber in) your swimsuits.

Personally, I think that the rule of using no CYA is a "black-and-white" "either/or" over-reaction to a real problem of having too much CYA. So I'm conflicted as to what to truly recommend. My gut feel (based on the information that I know) is that a small amount of CYA would be OK, but to keep it as low as possible such that it allows you to maintain chlorine levels (since running out of chlorine even with no CYA is obviously much, much worse). If your hot tub can maintain chlorine levels with an amount of CYA that barely clouds up in the CYA test and is therefore quite small (probably 10 ppm or so), then that might be a decent balance between chlorine disinfection and chlorine preservation, but I honestly don't know for sure.

Richard