I'm something of a newbie to aquariums (and the forum), so forgive me if the answer to my question seems pathetically obvious.
I have a twenty gallon aqua-terrarium (so it's about 3/4 full, with a "log" sticking out of the water) with two female betta, two small algae eaters, and snails (blasted Petsmart plants). The filter is one of the kind that hangs from the inner wall of the tank and shoots out filtered water near the surface. It makes a noticeable current in the tank.
There isn't any real current to speak of inside the "log".
I've been seeing in certain threads on the forums that betta don't like currents; I know that they're essentially ditch fish. Sure enough, mine tend to hang out inside the log or between the filter and the aquarium wall. They will occasionally appear to "play" in the current (swimming into the output of the filter, being pushed into the current, and then swimming out of the current and back around again), but I don't know enough about betta psychology to really interpret the behavior.
Should I be worried about the current stressing my betta? Should I downgrade to a less powerful filter? I don't think one of those filters that sits on top of the tank, sucks water up, and then waterfalls it back down would work well with the aqua-terrarium setup. I've tried an undergravel filter in the past and grew to despise it. Any other suggestions?