First off I would like to thank everyone for their time and effort. I'm pretty new to this hobby and really am enjoying learning about marine life. I have a 40 Gal
tank with Fish and Live Rock (main tank and Refug setup). Tank is about 4 months old. I only have two fish, a Clown Fish (2 months in tank) and the Spotted Puffer (3 weeks in tank) . I also have some snails and small hermit crabs. All of my water parameters look good (A-0, Ni-0, Na
-0, pH-8.0, Sal-1.023, phos-0). The problem started a few days ago with the puffer starting to hide under a large rock. I noticed when feeding (frozed brine shrimp) he would eat the shrimp but spit them back out. As of today he is staying under the rock on his side and is breathing heavy. He does not appear to have any signs of physical problems or disease other than the breathing. I'm at a loss as to what the next step should be. I could pull him from the tank but I do not want to stress him out if there is better advise out there. Also the clown fish shows no signs of any problems. Thanks again.