I have 2 propane gas tanks hooked up to my cooktop only and use less than 40 gallons/year. My supplier is going to change the setup from two 100# tanks to one so I meet the new minimum usage requirement, even though they'll have to fill the tanks twice a year instead of once. Anyway, a friend suggested I look into connecting those 20# propane tanks (used with gas barbecues) which I could maintain myself. Would they connect the same way? Are any adapters needed? Is there anything else I should know about doing this? (I'm working on price comparisons.)

The first thing to do is call your local building inspector to ask what code is where you live.

Totally different regulators and pressure. I read where you said "use less than 40 gallons per year" and then you said "will have to fill then twice a year" In a 100 Gallon tank, they should need to fill 1X every 2 years. Why not buy a 100 Gallon tank and then you can fill them whenever you like. I have a 250G owned tank, filled 1X per year and I can use anyone and get a cheaper rate since they know I can use anyone.

There may be some confusion between 100# and 100 gallons. I think a 100# cylinder tank like what I have now holds about 24 gallons. The 20# tanks used for BBQ grills hold abut 4.8 gallons.

You would have to change out the cook top to do this, for one that would work with the difference in pressure from the tank. If your usage is so low, it may be worth it, if the zoning lets you get away with it. Also they make a slightly larger tank, ( sort of looks round) that should be more than enough,

OK. Understand. You could still buy a 100G and fill it every 3-4 years. Regulator should be the same. Propane never goes bad!

I've learned that my propane supplier only services tanks they own, so if I located one to buy, I'd also need to find someone to fill it. There are limited options in my area, and I'm also wondering about having the tanked checked for safety from time to time. I've learned that the 20# propane tanks can have diminished pressure in cold weather (I'm in upstate New York) and this could affect the functioning of the cooktop in a negative way. Since I figured out that using the 20# tanks would cost more, need frequent refilling, and be unsafe, this was an easy decision after all. The second 100# tank was removed two days ago and I'm all set. Thank you all for your input.

Too bad they only service their own tanks. That means you pay more than market. I am in the N. GA mountains and have 3 suppliers who will service me.