Re: bulge in potable water tank

On ours the FW tank bulges down when full. It is because the potable water tank is made of a more flexible white plastic stuff than the more stiff dark coloured plastic used for the grey and black tanks.

Not had any issues with any water left in there when "empty" if there is any. Ours does not need any extra supports underneath. In fact a support would stop it from bulging down so where would it bulge instead or would it just not fill as much? Not a clue.