One of my five Angels is pointing upward instead of horizontal. Is that a sign of swim bladder disease? If so, how do I treat it and if not what is causing this? I have a 210 gal. tank. do 30% water change every other week. Also check water quality. All ok, except I have a problem keeping ph levels at 7.0 usually when testing for ph it's at 6.8. Other tank mates include: 6 Clown Loaches, 5 Blue Gouramis, 2 Gold Gouramis, 1 Moonlite Gouramis, 5 Boseman Rainbows, 4 Mollies, 1 Pink Tail Chalceus, & 2 Chineese algae eater. Thanks for our help.