Could someone give me some advice I'm fairly new to saltwater aquariums we've had ours about about 5 to 6 months So obviously still very new and still very early as we are going through all the algae blooms and all that fun stuff lol. My Valentini puffer started acting weird a couple days ago and I noticed he was pinning himself under rocks and tonight when I moved the rock, I noticed he was floating upside down and stays that way unless he pins himself under a rock. My water is good I tested it again and everything seems fine I have moved him to a hospital tank to segregate him from all the other fish can someone give me advice? Oh FYI we were treating the tank meeting the tank with some medicine that the local saltwater fish store told us to put in there because we thought one of our other fish might have had fin rot but that's the only thing we did different..