Ist if you are hooked up to 30amp and not50amp. you will flip breakers when trying to run A/C and other major appliances. AT 50 amp you should be able to run about what ever you want. As far as the knots I'm not too sure, We camp in Colorado during the summer and many things just don't happen. I would use digest it in the black tank. It gets rid of a lot of problems and its just bacteria. Just follow directions properly. Always make sure black tank is closed and when dumping black close the gray tank, At times you will need to let the gray get some water and put digest it in for about 24 hours. That will get rid of odors in gray tank.
as far as sensor lights. They just seem to have problems. We just know to dump black once per week. If you are hooked to 50 amp, you might need to get electrical system checked. 30 amp, just won't run everything.