Just my two cents on this one - I have noticed that mine (the orangish-yellow kind) DO come out at night and STAY out at night BUT, I've "trained" mine to come out when I feed the rest of my tank. I have a switch for my return pump and I flick it off before I feed. Seems like EVERYTHING in the tank now knows that when the water isn't swirling, it's time to eat. Within 5-10 minutes of switching off my pump, the sun polyps have opened up. I feed mine a mix of brine and freeze dried cyclopeeze with a turkey baster. The only problem I've had with this method is that my Pajama Cardinals recognize the turkey baster and cannot be scared away with a flick at them with the turkey baster, To get around this problem, I've cut the bottom off of a 20oz soada bottle and I put the turkey baster's nozzle through the neck of the bottle. I can then selectively feed three or four polyps at a time (and the bottle keeps fish from swiping the food away). Sorry to by so long-winded, but I feel that I have been successful in keeping sun corals without spending a fortune or too much time.