It has occurred to me lately that LED lighting has a complete lack of UV light. some UV is necessary for correct coral Growth. have you heard anything on this? it is still early in the game for long term exposure studies, but they seem to work fine for me and everybody else. just I need to know.
Now, sps near the surface in nature obviously get some UV. The Zooxanthellae (Chlorophyll A peaks in the 410-420nm spectrum which helps feed the algae) can get this needed UV via 420 nm light (Chlorophyll A peaks in the 410-420nm spectrum which helps feed the algae). Blue LED is typically 450 nm +- a few, not near enough to UV for some Zooxanthellae to thrive. Granted it doesn't affect many corals in general, but there are several SPS than need the UV light to thrive. Growth rates also can be slower over time with some sps without any of the "damaging" UV at all. Go down few more feet to another reef zone and UV doesn't play such a role.
There hasn't really been a lot of time to study this in the long run I feel, and I am not affected personally right now as I don't think I have anything affected by lack of UV. All the same, this seems like a hot topic.
There have been reports of some pigment loss and morphing of certain SPS under LED only. Several (most) manufacturers are now including UV chips to their LED systems, I wondered why and think I understand. I don't have any sps corals that grow out of the tank seeking more light right now, but some people have some exotic stuff out there!
Does anyone have any observational experience with this, or any input for us here here?