Over the last few days, i noticed that my polyp has been shriveling a bit on one side. All of his tenticles type things are missing a small portion of one side. what could be causing this? I have had him for about a week and he has been open every day except yesterday and today where he looks a bit shriveled. Water paramaters should all e fine, i just checked them not too long a ago and did a 20 gallon water change a few days ago.