Red Light
[cue dead horse]
I think it's easy to read too much into that quotation because a lot has been left out.
Corals that do receive red light
react because of the stress associated with red light.
The reason that red light is associated with stress is that
surface light is BRIGHT and deadly.
Many (most?) corals are stressed and apparently not as healthy under surface lighting conditions (studies show they heal from injury much more slowly than healthy corals at lower depths, for example)....presumably due to oxidative stress and having less energy to spend on their own upkeep. Corals are surviving at the peaks and depths of their light range, not thriving.
Also, the examples are specious. Here's why:
The Radion (as far as I can tell) was designed to emulate the truly respectable Radium 20K bulb. Ok, I saw Vivid's tank (online), I'll give them credit they did OK.
But the Radium bulb was designed for industry, achitecture - maybe even specifically for Lloyd's of London(see bottom of post)...I dunno. But it for-sure was not design for reef lighting.
He may not know it or whatever, but what he omits is that hobbyists selected the Radium
because it didn't stink royally like the lighting that came before it! Whether the red in the bulb had an effect on "rendition" or algae (et al) was NOT a question at the time....it was the blue we were after and what made it popular.
Coral Collection
As far as where corals are/are not collected.....I think that's an interesting question that will still deserve a good answer after this thread.
I have yet to find any authoratative data (with even just a hint of authority....nothing fancy required!) on where any hobby corals are collected.....which leaves us to infer a lot and guess about species.
80's and 90's - That said, word on the street back in the 80's and 90's was that a lot of the corals were collected by ordinary divers - not SCUBA which is
expensive. "Ordinary divers" implies a very shallow collection range, and back then (it was said) the vast majority of corals were from shallow water. No doubt this collection is still happening, at least to some degree - cuz you can't beat cheap.
2000's - Supposedly (again, "it is said"...no data) in/around the 2000's (when it was clearly becoming a speculator's market, and the word on actinic light was out on the diving scene) it became more common to have specimens showing up from "deep water" that were much more colorful compared to what was showing up in the hobby through the 80's/90's. This is logical (and parallels the 1000% price spike in high end coral frags), so I tend to believe it.
"The corals are the most diverse on the reef slope between five and twenty
meters of depth[...]"
From:
http://www.eoearth.org/view/article/151489/
That's between about 15 feet and 60 feet - the first zone of light that's red-free. This is where the corals seem healthiest too. Seems like this should be the model we're working toward.
So as a rule of thumb, if a coral is colorful, I genearlly say it has no business seeing red light (as far as it is concerned).
A pic for the reference above...
No that's not a building full of reef tanks tucked into that cityscape.
That's the Lloyd's of London building! Radium 20K's!
