Stupid sounding question, I know…but sincere.
Draining an indoor spa which needs more time to oxidize the combined chlorine, when slamming, than I care to wait. This will be following an AA treatment for imbedded rust stains.
So the question is this: Will leaving a percentage of existing water in the spa cause the combined levels to build up quicker.
Say starting full cc is 3; if we drain and refill ¾ of the water (theoretically) the cc should be 0.75?
Will leaving a small amount of old water actually cause the cc to build up quicker, or is it only the new starting point (0.75) and the levels will build up at the same speed as if all the water were replaced?
We’ll actually probably replace more like 80-90%, going any lower will cause restart drama with the pumps, but so will a rapid re-accumulation of cc cause undue grief.