Clown Trigger with a bloated stomach?

[robocop]

My Clown trigger is acting sort of strange. It seems to sleep a lot until it’s time to eat. It is also a little shy now a days. It’s stomach looks somewhat bloated and I saw it role over once. I’ve had it for about 2yrs now and the tank is well established. All the other fish are fine and I just changed the water and cleaned the tank so all the levels check out fine. The [acronym:117b9a5750="power head or Measure of the concentration of hydrogen ions, depending on context"]ph[/acronym:117b9a5750] was around 8.0 but I’ve been adding a buffer to raise it. The other fish aren’t picking on it because it’s the biggest badest fish in the tank but It does not seem to be very active lately. Any idea what could be wrong? My first guess was it is taking in some air some how. There are a few micro bubbles here and there but not a very noticeable amount. I only feed 3 times a week and I feed them just enough for them to get full but not over eat. I notice it’s stomach on the day I don’t feed also. No other fish in the tank is showing any of the same signs.