I found a local supplier for food-grade CO2. Dry ice is $22.95 for 10 lb of nuggets. Liquid CO2 is $25.77 to fill a 10 lb tank, but I have to bring my own tank. I found instructions to use regular pipe fittings to make extracts using liquid CO2 instead of alcohol or butane. Sub-critical liquid CO2 extracts are supposedly the bomb. I guess the wife's new floor will have to wait while I spend next month's Social Security on stainless steel pipe fittings. By my stoner calculations 10 lb of liquid CO2 should fill a 1.25" x 6" pipe nipple with an oz of weed in it about 20 times. Has anybody tried this yet?