Well today my etc right at a year old. he is floating tail up face down. when he swims he will barrel roll, but is breathing fine. Feed him last night and his tank mate is a arrowanna thats still swimming and doing fine. I tested water alkalinity is low, but ph is fine could this do it. How do I fix it. I have done a water change today with stress coat any tips. Thanks also in a 180 gallon only arrowanna and him.