I recently began stocking fish into my new aquarium to try and keep the bacteria alive and decided on some corys to be the first addition. After 48 hrs in the tank the two "peppered" corys started to really show differing behavior specifically when I fed them. It seems that while one has continued to act as they both did at the LFS (swimming leisurely around the bottom of the tank) the other has taken to playing in the filter output and sitting itself on top of the ornamental buddha. I sprinkle a pinch of flake in to let sink and the "normal" acting one goes about its business eating as it trolls the substrate. The really active one has figured out that the flake dust that didn't sink pools at the grate of the intake and will position himself there to hoover it all up like a little vacuum before swimming laps around buddhas head. Is this a normal behavior? According to the water test kit the water itself is at safe levels, so I am unsure why the one is being so active and avoiding the bottom of the tank.