I absolutely love bubble corals and I have two in my tank. During the earlier parts o f the day my large bubble coral the green opens wide, however it seems as if it is closing up more than what is used to do. It seems to close up more as the evening approaches. See picture where it is closing up. The smaller bubble coral stays open all day until the lights go out. I had the water tested today and the store said everything was fine including phosphate and Calcium. I have a 65 gallon Oceanview aquarium with T5 lights 3 white and 2 blue. At first I only had 2 white and 2 blue on. I recently turned on the other white bulb. As anyone seen this type of behavior in their bubble coral??? I feed it the small pink ship that you purchase in the pet store. I feed it once a week. Could it be the light?
