Quote Originally Posted by chem geek View Post
I forgot to add that with a hot tub you are sometimes fighting Combined Chlorine (CC) because some hot tubs are not exposed to sunlight. If that is your situation and you measure CCs consistently, then the regular (weekly) use of a non-chlorine shock (potassium monopersulfate) will prevent this, but it will also measure as CC itself unless you use the Taylor R-0867 reagent (found in kit K-2041). This same advice also applies to indoor pools where keeping CCs low is difficult.
Richard, I think you have said in the past that shocking/superchlorinating doesn't really breakdown the CC. Is this correct? Is that why you are recommending using non-CL shock as opposed to super-CL?

Would exposing the spa to several hours of sun breakdown the CC? (Not sure I want to add YAC - yet another chemical - to the small amount of water in my spa).