Just a followup KiotiJohn, I haven't had time to answer. I have used an additive by SNAP in every 5 gal can I can remember since it was new. The SNAP, about like most others says, "it is a Diesel Fuel Treatment, and anti-gel supplement" 32oz for 40 Gal. I used the last of the SNAP and bought the Power Service because of the talk about it here. It (PS) is supposed to prevent gelling down to -40 F, but 32oz of that is good enough for 100 gal, so I suspect it is more concentrated. I just re-read my original post and it looks like I said I have been using the PS all along, that isn't the case. The SNAP product is what was in the tank.
I drained the old fuel into a 5 gal white bucket so I could maybe see down into it if it was water but I couldn't see any water and it didn't gel up sitting outdoors during this cold weather. Now I'm not sure what to do with it. Do you suppose I could put a few quarts at a time into a full gas tank of one of my cars to use it up? Probably the fuel would be perfectly good during warm weather.