Characteristics: Bismuth is a brittle, silvery-green metal that has a low melting temperature and high specific gravity. Being both stable and non-toxic, bismuth is often used as a replacement for toxic metals such as antimony, cadmium, lead and mercury.
1 (Minimums vary by location and tank size, and can range from 100-1,500 gallons.) More often, the propane company charges a fee of anywhere from $25-$250 a year but averaging around $75-$130 annually, depending on local rates, the size of the tank and whether it's aboveground or underground.
I'm only familiar with prices in our part of the country, but prices range from $12 to $18 to fill a 20# cylinder, which is about 4.7 gallons of gas. Some tank exchange services only put about 18# of LP in the tank.