Well there are DIY water bottle filter baffles that change the water movement to the side of the tank, instead of all over the tank. I think that is something worth looking into. I did that with my 20g, along with an intake baffle. At one point and time, I did an intake and outflow sponge baffle, but I'm liking the DIY baffle more.
I can't find petsmart's filter sponge, but that's what you want for an outflow sponge baffle. Though I'd suggest the water bottle outflow + sponge intake baffle combo for the least water flow possible.
step-by-step DIY water bottle filter baffle:
Here's a good sponge for intake:http://www.petsmart.com/product/inde...AvailInUS%2FNo
What an intake sponge covering looks like cut to size: