I have used the reeflux 12K bulbs, Icecap 14k bulbs, Reef Grow 15k, SPS 10k & 20k, XM 15k and a host of other brands over the years. Out of them all for coral growth I would say I have had my best results from the Reeflux 12 bulbs & the Reef Grow 15k bulbs. But this is just my 2 cents.