My toadstool has been growing by leaps and bounds. It will normally be fully opened within 15 minutes of lights on. Sunday evening, I did a water change, only 8 gallons out of a 150 tank. The leather closed up during the process and has not opened up since. What could have made it so unhappy? The sg was the same. Is it normal for them to do this? None of the other corals, nor the anemone, seem upset.