Everything I have heard about them is exactly what CD said. They require good current and a constant supply of phyto. That would get pretty expensive with DTs. You would have to set up a phyto reactor to keep them. It would take a species tank. The good news is that they don't require any special lights because as Denise said, they are not photosynthetic. They typical live hanging upside down in caves and under ledges feeding on phyto they catch in the current.