To simplify the outcome of most of the debates: it appears that some types of Coralline Algae prefer higher lighting, while others prefer lower lighting. Many aquarists have found that, as their tank lights get older and the spectrum and intensity fades, some of their Coralline growths actually increase and grow higher in their tanks. They also found that these growths die off in the more well lit areas and increase in the lower and/or more shaded areas of the tank when the lights were replaced, while other types increased under the more intense lighting.
So what type of lighting is best? There is no single answer. Some types of Coralline will grow better under certain lighting while other types will grow better under a different lighting. For the most part, it seems that Coralline will grow under minimal reef type lighting (our Corallines do well under 1.6 watts per gallon of a combination of 10000K and Actinic Blue). In his CORALLINE ALGAE PROPAGATION RESEARCH PAGE, Leroy at GARF states that: "Lighting the live rock grow out tank with 2 Triton 40 watt bulbs to each Blue Moon 40 watt bulb has produced the fastest growth of Coraline algae."
