If I were you though, I would ditch the tubes and go all CFL, for flower anyways. I use tubes for Veg and CFL for flower the reason being this....my 4 ft tubes are 40w a piece, 80 overall. I can use 3-4 CFL's 26w's and place them around the plants to maximize my lighting. Same amount of watts but I'm getting more from them. Ya dig?