the 20KK bulbs IME give much better coloration but less growth.



True in some cases but not all.. I have found that many corals color best under
6500k iwasakis (coloration is better because of the MUCH higher PAR) and some
corals color better under 20000K radiums.. (Less par but higher Kelvin). here
is an example of a mille that has been under Iwasakis only(no actinic).. under
Radiums this coral was not half as colorful as it is under Iwasaki 6500k.
http://www.asplashoflife.com/magneta.gif
Rod Buehler
www.asplashoflife.com