I purchased the photon48 lights a few weeks ago for my 120g 4x2x2. The spread is adequate for 48 inches length side but not adequate for 24 inches front to back with wall to wall coral. Would be perfect for a 90 that is 48x18 if you mount them 10 inches or more off the water.
I am also disappointed with the spectrum though. Too purple for my tastes and generally the tank appears too dark like it's not enough light. Although the corals do look great, but the fish do not. The yellow and blue tangs colors just aren't as impressive and bright as they were under the Chinese LEDs I had before.
If course this could be partially because I don't have them run above 70/35 power wise so maybe will look brighter if I can get closer to 90/45 or 100/50
Thanks, i appreciate the insight. my tank is 48x24 too so..
That was kind of my concern after seeing the recent youtube video by reef dork, although he's euro and has the evergreen version of the light. but it just looked.. dim? spectrum obviously varies and who knows what he had it at. i know of an lfs near me that has some reefbreeders so i still want to go check it out to see for myself