I have a 2016 376bhok Could someone help me understand the plumbing system? We have a front bathroom with sink.We have a full bathroom in the back(toilet,shower,sink. We have a set up for washer & dryer which is not being used. We have a kitchen sink in the middle of trailer and a outside kitchen that has a sink. We are on our first trip and have be in it for 5 days. The lights on the panel say: 1 black empty red light. gray empty red light galley 2/3 red light 2 black gray and galley all empty red light. We are using city water. Black is sewer, Gray is sink and shower. What is the galley tank?