nice find i cant find any anywhere anyway red sun polyps inhabit shady areas and caves in the wild where they don't have to compete for survival with photosynthetic corals in order to thrive. It is widely published that the Tubastrea coral needs to be place in the dark or in a shaded area. Well, I am going to disagree with that and say that it really does not matter where you place them in the home aquarium B) . As long as they are getting regular feedings, they could care less about the light. I think the reason for the dark references is more to keep unwanted algae growth off of them when they close up. I have my sun polyps right on top of my tank using power compact lights and they open up whenever I feed them no matter what time of day it is.
I agree, sun corals do not need light for growth. It wont harm them however if they are placed in light. they might take a while to adjust to this but they can be trained to open during the lighting period of he tank,