i agree with dylan.....UV lights like MV (mercury vapor) lights are very very extremely rich in the red spectrum, they are propably only red spectrum and they boost thc production as they are harmful....i am getting two of those MV lights(125 watts each) used for aquariums as well to use them for a couple of hrs every day in conjuction to my 400 grolux hps lamp.....in this way i hope to maximize the size of my buds!