My "reef" tank is still kept at super low temperatures (high 60s), and the corals are growing. The acans is developing new heads like there is no tomorrow (and they have the same great color as the original heads from when I bought it months ago), the trumpet divides new heads as long as I feed it every once in a while, the gorgs are growing and putting down new tissue, the zoas, palys, and 'shrooms are spreading.... The only coral that I wouldn't recommend on purely a temperature incongruency would be blue ridge coral, as that is suppose to like really warm water.