The flags (in my tank) mostly stay towards the bottom/middle of the tank. But- they DO swim at all levels. I've never kept them in an aquarium without two currents. The filter (waterfall filter) and the fountain pump (bottom of tank). They like the faster flow of the fountain pump.
These are the only kind of shiners I've kept-that I can remember,lol.
Another thing- they LOVE having a fallen limb to swim under. It's hard to see in my tanks pics, but they have one there. Everytime I've found them in the wild- they are under a limb in the current. HTH's! These are neato little guys!
(stupid typoes!) LL- you replied at the same time i did! LOL