Q. How do I know how much water is in the toilet fresh water tank.
A. The amount of water is shown by the sight glass to the right of the photograph.
Q. The fresh water tube is full, does that mean that the fresh water tank is full?
A. Not necessarily. The fill tube is "U" shaped. The way to know if the tank is to look at the sight tube shown in the next photograph.
Q. The Thetford manual says I should add chemicals to the fresh water tank. Should I add the deodorant to the fresh water tank?
A. No. The chemicals that Thetford discusses is not available in the US. Adding deodorant may damage the toilet seals. It should only be added to the cassette black water tank and read the directions regarding the amount of deodorant to add.