I switched from 20# to 30# tanks a few months ago. I think I might have a leak though. I went through 1 30# tanks in a few months. When I open the top of the hard plastic tank cover, and stick my nose in there, I get the faint whiff of propane. I checked with soap & water a couple of months ago and didn't see any bubbles. But maybe I wasn't thorough enough. Has anyone used a propane detector?