Maybe someone with a Red Sea ATO can help me. I have read the manual and watched the videos, but this is not covered. I have been setting up my 350 G2+ this last week. Two days ago, the ATO kicked in for the first time. It worked as it should, pumping water into the return chamber. This morning, I could hear a slight gurgling sound and noticed the ATO did not kick on. The light for the pump on the controller was not lit up like the rest of the lights. I pushed the manual fill button and was able to fill, so I know the pump is working, but the pump indicator on the controller does not stay lit up. Should it be on continuously or only when it runs? I also don't know why it did not kick on. I will try cleaning the sensors, which has been recommended in other threads. I appreciate any advice that is offered.