ok its my turn to get some answers hopefully It seems like my biggest chromis started acting weird 2 days ago he doesnt swim around like he did and hasnt eaten. he just sorta hangs out in one spot. thing is his color, fin, skin, eyes still all look good and hes still heavy (healthy looking). i watch him swim and he swam along the rocks like he was feeling his way around and he swam into another rock and into a coral almost like he couldnt see them. the tank has been going for almost 2 years now and ive only lost one fish out of it but this fish was one of the first i had gotten and was in my 39 gallon tank when i had it so its been well over 2 years. could it be old age or maby someting else has happened. his color is as green and blue as ever and he doesnt look sick. so this is one i cant seem to figure out any help be appreciated i have 5 of them and him and the other biggest one was always together like a pair. the other one seems to swim up to him and bump him or sit next to him as to say come on lets go. but he doesnt take off with his mate or the group. they try to get his attention but he doesnt swim to far.