My bala sharks have recently been added to my new 40 gallon tank yesterday. It is not cycled but I have been monitoring ph and ammonia, nitrate, and nitrite levels. They are all good. The tank is at 78 degrees. But my balas seem to be very twitchy and are constantly opening and closing mouths. They also like to stay in one corner of the tank. They are not going to the top for air. What could be wrong with them? I have 2 balas and 1 plecostomus in the tank. The plecostomus is doing fine.