I also must add that I have had one of thes guys down in the corner of my 33g cube tank for about 2 years now. He has never moved from that location and as usual only opens at night. There is a purple anenome living about 2 " away on one side and a gbta about 6 inches above him with no issues that I have ever noticed.
They are interesting critters, if you are concerned with him in the tank, maybe someone would like to take him or he can go into your fuge?