Orbit Marine LED?

They use an Epistar LED chip at 1/4 watt. Epistar is not known to be the best LED. Not efficient (by LED standards) and you need 72 to get 18 Watts. 72 of my DIY leds yeild 216 Watts. The colors are pretty close to Royal blue and cool blue and the whites are toward the higher end of the spectrum (~4800-5200 are neutral white). Not to dissuade you on these, but the one Adam posted on the forum a few days ago looks to be a better light and at less than a 100 bucks you can't go too wrong.

Fat

Redleader, We used Bridgelux Royal Blue and Neutral whites they are all 3 Watt pm a star. They have been very dependable and I and satisfied with my tank. There are 24 LEDs on each heat sink. I use 4 of these on my 102 gallon so I have 96 total LEDs @ 3 Watts each. I control it with a reef angel controller. I can control either the blues or whites from the controller, cellular phone or an internet connected computer.

We use two of these fixtures on my son's 55 gallon aggressive tank. He's using the same leds, heatsinks and meanwell drivers (ELN-60-48) and controlling it with a Typhon controller some of the guys on Reef Central designed. We built it ourselves. There is some new software out for it that makes it easier to run. I installed one on a tank for one of the guys here when his LEDs died and I fixed them. His old system used an electro-mechanical clock to run them.

If I were to do it again I'd do it differently though. Since we built ours, they have brought out some great LEDs. You can get Bridgelux Veros for white and most of the other chips in 4 and 6 up packages where they have four or six LEDs mounted on the star. Some even are under the same protective LED dome. I'd still run it off a Storm controller, but use Meanwell LDD drivers to drive them at the proper current. The newest thinking is that the LEDs should be clustered together in packages v. evenly spreading them out on the heatsink. There are a lot of options out there. For control, color and an absolutely magnificent build you should look at Reef'd Up's system. All run by an Apex

Let me know if you have specific questions.

Fat

Aw! Thanks Fatman! Fatman and Krazie4Acans are the ones who really know LEDs here.

But to add to the discussion, the ones you posted give out practically no PAR. It's been a few years since I last looked at the latest research on coral PAR values, but last I saw, 50-150 on the sandbed is ideal as a minimum. The lights you spec'd out have practically no light hitting the bottom of 24". The only stuff you could healthily keep in the bottom of a tank like that is nonphotosynthetic stuff.

There are much better lights out there that are still inexpensive. :)