I had 14k bulb and geismann atinics as supplement lighting and it looked fantastic. Gives the corals an extra pop and create a dawn and dusk period, instead of just shocking them with the mh alone. I agree the 14k gave me great growth but the t5 set up I have now is better imo and the growth isn't too far behind. Heat and energy were the main issues with the mh. If it wasn't for that I would go back to my mh, t5 combo.