About SPS color and LED lighting

[BonsaiNut]

I'm a little confused with LED lighting and some of the concerns about SPS / invert coloration, and was hoping I could get some help.

It has always been my understanding that photosynthetic creatures had two sources of color: (1) the coloration associated with their zooxanthellae and (2) pigmentation that had nothing to do with zooxanthellae. Based on a number of papers I have recently read associated with coral bleaching and adaptability of photosynthetic creatures on tropical reefs, some pigmentation appears to be a protective response to increased levels of UVR. In other words, in shallow waters and brighter sun, some corals increase their pigmentation (and coloration) in order to shade / "protect" themselves from ultra-violet radiation.

Having read several threads about SPS color fading under LED's, I am wondering if the approach of rating LED's simply on PAR is not the complete story. Clearly we can keep high light corals alive and thriving under the high PAR levels of LEDs. But shouldn't people be thinking about some other "intensity" or UVR factor that triggers elevated pigmentation levels? Isn't there some other story here to LED's beyond simple PAR?

Perhaps there is already a discussion about this on some other thread, but I was hoping for a more definitive: "here's what MH has that LED lacks" on a more scientific level (evaluating spectral intensities, for example) so that I could better understand what I would be looking for to add to a standard LED setup to get it to truly equal the spectral intensities of sunlight (or whatever is needed for high pigmentation levels in coral). I know LED's are quickly evolving, and costs continue to drop (50% every three years is the current estimate) - do we know what we are looking for from the future of LED's beyond PAR?

[Anemonebuff]

Some have been adding UV LEDs to their LED arrays.