I don't know about converters, but I do know that T-8 and T-12 fluorescent tubes require different ballasts. 15+ years ago I purchased some cheap, used T-12 fixtures with old ballasts. The ballasts were quite noisy (and probably not long for the world), so I replaced them with T-8 ballasts. This wasn't difficult. They work just fine, and the T-8 tubes fit the holders for T-12 tubes. T-8 tubes appear to be more energy efficient that T-12 tubes. High intensity T-5 tubes are wonderful for growing plants that need a lot of light (I've flowered Cattleya orchids under mine), but they do increase your electric bill! Eugene Zielinski Augusta, GA USA > [Original Message] > Subject: [pbs] Plant lights > > I hear that T12 fluorescent tubes are obsolete and will soon be unavailble because of government mandate. I have many T12 fixtures and have read that one can purchase a converter that enables T12 fixtures to handle  T 5. Does anyone have any experience with these conversion pieces? Dell _______________________________________________