My favorite bulb is the radium 20k. I just didn't feel it was necessary to spend that kind of money on a tank with little coral so I only run radium on my reef tank. I like 20k because I like color in the tanks. I suffered through 12k bulbs for 4 months and that was enough for me, a yellow drab tank just isn't appealing to me. As far as the cheap bulbs go there doing great. I have some montipora, chalice and spongodes under them and there growing like crazy. I will say that the cheap bulbs in 20k are more purple than a blue appearance. Even though there doing good I still couldn't risk putting them on the reef tank.