tank separation

[Malt_Vinegar]

I have a four gallon tank that i would like to split into two compartments in order to allow me to keep two bettas together in one tank. However, the filter is a small powerhead fluval one. So water flow between the sides is very important to ensure both fish get filtered water.
What should i use to separate them?

 

[juliethegr8t]

Off the top of my head I'd say that some of the plastic "mesh" type material from a craft store might work. I have used it as a lid on a few of my tanks - it's great stuff. It has larger holes than normal tank dividers, so you'd get better water flow. However, with a divided tank you're still gonna run into some filtering problems, unfortunately there isn't a great way to work it.

Sorry I have no clue what it is technically called. If you haven't seen it, it's used with special yarn to sew patterns on it. However, the holes are good sized.