I added an external monitor to watch the water level in the tanks while standing outside. This saves the running back and forth to monitor the tank levels while back filling and flushing my waste tanks with a Flush King. I could also monitor the water level in the fresh water tank during filling.
Please see this link to FiberglassRV.com for details. http://www.fiberglassrv.com/board/in...topic=30774&hl