Normal Cory behavior?

[Mr-Furious99]

I have a sterbi cory that that likes to swim up and down the side and back of the tank. This isn't all the time but the last few days he's been very active. I've done water changes twice in the last three days as well. 0.5 ppm ammonia, 0 ppm nitrites, 5 ppm nitrates. The other corys in the tank just do their thing on the bottom of the tank.

 

[Byron]

This can be indicative of a problem, but it can also be nothing more than an energetic happy cory. Some species do this much more than others; my pandas are always swimming, and they enjoy doing it in the filter current, which is to be expected given their habitat is a mountain stream in Peru where the water is cooler and flowing much more than for many other species' habitats. Fish behaviour is programmed into their DNA which is why we must always attempt to provide as natural an environment as they expect.

Sometimes water changes encourage this, or at any rate more active interaction, even spawning; to the fish a water change is like the rains of the wet season when they spawn. Your sterbai is likely just happy.