The trailer we purchased has 2 40 lb propane cylinders on it and you have to switch between one tank or the other, we purchased late in year so did not seem to use much gas so not a big deal but we are opening up in another week and will definitely be using heat more I would guess atleast for the month of april and part of may. Do they make a regulator that will attach and draw off of both tanks to eliminate the need to switch from one to the other? I could be wrong but I thought the one on the trailer didn't draw off both at once, am going up this weekend to measure for a piece of furniture so will double check but I thought the system that was on it didn't allow it.