light required by diferent corals

[Aquattro]

Steve, I don't think the phrase "SPS should have as much light as it can get.." is entirely accurate. Many SPS aren't huge light hogs. In fact, too much light too quickly will almost certainly damage and/or kill a coral quickly. Excess photosynthesis can cause the buildup of O2 within the tissue and burn(oxidize) the coral from the inside out. I noticed in my tank that even suddenly moving a coral 6 inches closer to the light caused some short term stress. My E. ancora is spewing zooxanthallae due to higher exposure. This is just by moving it directly under the light (on the sand) compared to partial shading it had previously. It will be fine, but if I had moved it to the top of the tank, it surely would be bleached by now.
I think since equipment required to measure umols of light is not standard reef equipment, it is mute to publish these numbers. They mean nothing to 99.5% of hobbyists, I'm sure.
Basically, you obtain a coral two ways: from other hobbyists in which case you have an idea of the lighting environment, or you obtain a wild collected specimen; you then use standard guidelines (1-10 scale) for lighting requirements and watch closely for an adverse reaction. When it seems to be doing fine, you can try slowly moving it higher in the tank if that's where you want it.
Basically, by knowing that a coral likes 30,000 umol/km * 5^2 litres inversely proportional to Friday night television programming means absolutely squat to me and therefore who cares. My corals like a lot of light or they don't. Part of being successful with this is learning to tell which from what.
P.S. See you at lunch! [img]tongue.gif[/img]