You may also want to take a look into the bulb/ballast combination on Sanjay's Site
to see how the PAR (photosythetically available radiation) values compare. The K
is the color temperature of the bulb. The bluer the bulb, the higher the K
. Generally speaking the higher the K
, the lower the PAR. That is not true, however with the CoralVue bulbs. If you could stand the blue-ness of their 20K bulb you get the best par.
The best performing bulb I've seen to date is the CoralVue ReefLux bulb. It has a very large spike in the blue wave length as well as spikes in the lower temperatures to help the bulb to appear more white while still giving you incredible colors on your corals. Some of the bluest of the blue corals I've ever seen have been under the CoralVue ReefLux 10K bulbs.
Good luck with your decision. Probably like asking people what their favorite underwear is!