I try not to violate my lights .....
I my opinion the answer to your question is yes & no!
I run the violet but not the red or green. I feel the violet mixes well with the blues so I don't see it in the shimmer or the shadow edges and it is more useful to the coral than the red and green. I don't run the red & green because they do show up in my shimmer and the do make some red & green shadow edges. They are marginally useful to the coral, the red more so than the green. The red is used somewhat in photosynthesis (not the green) and they are both used somewhat in making pigments and some other chemistry inside the coral. But I feel there is more than enough red and green mixed with blue in the white leds (white is a mix of the 3 primary colors Red, Green and Blue, thus the RGB acronym).
I run my blue channels at between 2 and 4 times as much intensity as I do my white.
Thanks for info! I am gonna turn off the red and green off for a few weeks, and see if there is any difference.
Most corals only really use the wavelengths from ~400 nm to ~500 nm, which is from violet to blue to cyan. Wavelengths bigger than that benefits algae more than corals. The colored lights <500 nm should be adjusted for purely aesthetic reasons, not for any perceived benefits of the tank inhabitants.
On the other hand UVA light from 360 to 400 nm can make certain corals fluoresce in ways that visible light can't. I'm not sure if these wavelengths are of any benefit photosynthetically.
Turning off the white lights and keeping only the blues running is a great way to combat excessive algae, at least temporarily until nutrients are reduced.
And the spectrum doesn't have to be in the 360nm to 400nm to make corals fluoresce. The shortest wavelength I have is a violet, probably in the 410nm range and and my corals fluoresce like crazy. In fact, I can turn off the violet channel and the corals still fluoresce the same with blue leds.
Yes definitely. The crazy thing is corals fluoresce differently with UVA vs violet vs royal blue lights. For example, some corals may fluoresce green with royal blues, but fluoresce pink under UVA.
If you have a blacklight pet pee detector, they're usually in the UVA spectrum. Check out your corals with them when all the other lights are off. You will literally see them in a completely different light!