If you have a smaller pond with stone around the edges where weeds grow, you might try a smaller weed burner like I bought. It's only $34.95 from brookstone.com and uses small propane tanks. It's very light and the only problem I've ever had is sometimes the flame goes out. If I go around the pond once a week (takes about 1/2 hour) I can get the weeds when they're small and pretty much vaporize them.