Three days ago I took four squares of Camco RV toilet paper and the same amount of what we use in the house. Both folded and placed in separate mason jars half full of water, no other additives. Af...
We use nice 2 Ply Northern. My Black Tank sensors show 3 out of 4 lights when empty after dumping. Often the 4th light will usually illuminate by the time I dump the Black Tank after every 7 days while long-term camping. The Tank has never been full within 7 days, but may start to stink a little by then in hot weather.
Galley Tank almost always shows all 4 lights all the time...
Grey tank when open usually shows only one or two lights.