help identify the problem

Hey! I've been trying to find some answers online but decided I wanted to get peoples responses who have personal experiences with them too. I have a young ornate bichir in my tank with some other fish, and recently he's been acting a bit strange. I'm pretty new to fish keeping and have been...

I have this replacement tank, for the tank whose stand gave up on life and I've been having problems ever since. The fish go pale and gasp for air at the water surface. Pleco and the rope fish are the only ones not doing this since they just get a bubble of air from the surface and use that for...