Check the chlorine level of the water coming out of your tap, mine is way over ten and people drink this, I don't I have a RO system, they bath their babies in it, cook with it, shower or bath themselves with it, so I can't see why sitting in a hot tub for 20 minutes or so will hurt you unless you have a strong smell of chlorine gas emitting from the tub, in that case you will probably have one heck of an overdose of dichlor.