I have a neon green pipe organ and he has been growing for over a year. It is on the upper rock work of a 90 gallon with 2-175 watt m.h. 15k xm's and 440 vho actinic. It gets direct current from the returns to keep any detritus and algae off. It continues to grow upward and outward and as it does the lower levels die off. I feed an array of foods for the corals. Hope that helps a little and let me know if you have any other questions.