Something I just found out and some of you might be interested in. You can refill 20 pound, 30 pound, and 100 pound propane tanks from the big bulk tank you have for heating a lot cheaper than taking them into the station and having them filled. Bulk propane tanks come in 250 gallon, 500 gallon, and 1000 gallon sizes and there are some even bigger. These are the big cylinder that sit outside the house, usually for the gas furnace. They have a connection with a valve and a tube that extends almost all the way to the bottom of the tank. This is so the propane company can pump out the liquid propane if they have to empty the tank to move it. The propane in the tank is liquid on the bottom and gas above. When you pull off the top it's gas and you use it for the stove and furnace. When you pull off the bottom it's the liquid. The connection is known as a wet leg and it has a built in valve that works something like the Schrader valve on your tire. If you push on it, it opens (don't do this without the apparatus securely screwed in because the valve may not close all the way). You can buy an apparatus consisting of several valves, a hose, and a connection to fit your small tamks. If you hook it up to both tanks and open all the valves the liquid propane flows from the big tank to the empty small tank. Viola, it's filled. Shut down the valves and carefully remove the small tank. Do this outdoors only in case some propane escapes. Wear heavily insulated gloves for this because any liquid propane that escapes will immediatly boil away and turn whatever it is touching very very cold. Of course no smoking or sources of ignition anywhere around. Propane is heavier than air so it sinks to the ground and spreads out. If you go into low earth orbit be sure and wave as you go overhead. Why do this? The answer is cost. If I take a 20 pound tank into town and have it filled they charge me $17 or over $4.00 a gallon for the 4 gallons of propane it holds. If I call the propane company and they come out and fill my bulk tank they charge $1.40 a gallon last I checked. So, to fill a 20 pounder off the bulk tank costs $5.60 vs. taking it in at $17.00. I asked the guy at the propane place and he can order the apperatus for about $100. I use the 20 pounders for the gas grill, the camper, and the ice fishing house. I will have paid for the apperatus after filling a dozen small tanks. There are 1950s vintage tractors that run on propane, have built in tanks, and fill the same way, so it isn't that unusual. Some propane companies refuse to fill bulk tanks with the apperatus attached. If you own your own bulk tank you can shop around to find the best price and one that will fill it with the apperatus attached. If the propane company owns the tank you may have to remove the apperatus every time they come to fill it. If the valve built into the tank sticks, it can often be closed by gently tapping on the fitting with a 2X4. The best thing about this is the gooberment and the EPA have not found out about it yet and closed it down, shuuuush. Get your apperatus before they figure it out.