I recently install a Red Sea ATO+ unit on my 20 gallon tank and as I was performing my weekly water change I noticed the ATO unit turn on and started pumping water into my tank. I thought this might happen so before starting the water change I turned off the auto-fill button on the app. Even though that was off the ATO still started pumping water into the tank. Am I doing something wrong? Is anyone else having same issues or can tell me how to correctly go about this, thanks.