HI everyone! I am new here but have been a visitor of the site since I got Opie. Opie has recently been staying at the bottom of the tank, usually on his side. His tail has seemingly continued to grow and the ends are very thick and flowy looking. He seems to have trouble swimming to the top and doesn't do so hardly at all anymore, except to eat. I am attaching a picture of him currently. My two gallon tank is cycled, filtered, and heated. I have a master test kit and all levels are in the safe range. I also perform 25% water changes once a week, while vacuuming the gravel. Any ideas?