I bought this blue regal from my LFS about 2 months ago and hes been doing very well, but today he's been acting sick. He's barely moving and now hes just laying on his side on the sand bed like hes dieing. I don't know what to do..Ive tested all my water parameters and everything is fine. I even did a water change and still nothing...I just don't understand how or why he would be dieing. Please Help