I actually just found out from a user on another forum that the flow is adjustable. So it would probably work.
On Fishforum.net nena posted:
"I have one running in a male plakats tank and I like it. It even has flow control. The filter inserts are super easy to replace. The tank if have it in is a 5 gallon and it does a good job. So good in fact that I have ordered 2 more for my 2 1/2 gallon tanks. The filter inserts are inexpensive also. I have been running it for about a month and so far it is very quiet to. The only problem I had was that with my acrlyic tank the inside of the lip around the top of the tank was to wide and the filter wouldn't sit all the way down on it. I just removed the lip of the rim in that section and it sits fine now. "
i use one of these in my betta tank flow is too much originally so i slowed it down and now it works fine, o an thanks for that link, that ones half hte price i payed for mine