I just added a new rock to my tank. The blue damsel found a cave in it and now he has been in there a day and a half and won't come out. He'll peak out and I can see him inside the rock so I know he is still alive but other than that I have no idea. The tank was running a little warm so I turned down the temperature to 80F. Even when I fed the fish he came out but didn't eat, when he ate like mad yesterday. This is a new tank and we have only had him for about four days, I did a water test and all the values came out fine. Any suggestions?