Replying to this old post. A fluorescent tube fixture can be converted or retrofitted to accept LED tubes. The existing tombstone holders in the fixture are then merely used to hold the LED tube. Current does not flow through the tombstones with LED tubes. The existing fluorescent ballast needs to be removed or just disconnected. I recommend removing it which is very easy. A good quality LED tube is one designed to be used with an external driver. The driver is like a ballast but delivers constant, low current unlike a ballast. The driver can be installed where the ballast was located or really anywhere in the cabinet of the fluorescent fixture. The best LED tubes I have ever dealt with our made by Titan LED. 12 year warranty but high quality. I have used a lof of brands and finally settled on Titan's brand. USA Made.