I work in the office of a plating company and have noticed that the chloride in our acid copper baths decreases in our barrel lines but increases in our strip lines (rack plating). This occurs despite the added water being of the same source, which has led us to use distilled water in our strip lines. Even with the distilled water, the strip lines' chloride levels climb rapidly while the barrel line's levels fall. I've asked at work why this happens, but have not received an answer. I've also tried to do some research, but have had no luck.