I don't have any experience with drip auto water changers (but I do want one in the future when I go MONSTER!!), but a lot of people don't worry about the chlorine in drip systems because their flow is so slow and the tank is so large that the chlorine is greatly diluted and evaporates before accumulating. I would see what your chlorine concentration is out of the tap and calculate the concentration if you do nothing to remove chlorine - also testing how long it takes to evaporate out. Also, just to mention if you have chloramines this would not work because those do not evaporate out of the water so the concentration would continually increase.