Sorry, I don't have much good experience with led but I can say 2 x 23W cfl is worthless. For my newborns I use 8 x 40W flourescents in a reflective box with the light about 4 inches from them. Never farther than that, with flourescents they can even be closer. Then I switch to a 400W metal halide about 14 inches away when they are about 2-3 weeks old