I bought a betta yesterday for my tank. I have read that they don't like much current - especially when first going from the little cups they sell them in to a tank. I looked at lots of photos and things on how to make baffles but none seemed to be workable for the Spec V.
I looked around the small pet store where I live for ideas and found a Fluval Edge "Pre-Filter Sponge" and was able to use that for a baffle. It's a cylinder shaped sponge with a hole in the center on one end that a tube would fit in, but the other end does not have a hole. I cut about half an inch off the end with the hole, and then just slipped the hole onto the out put thing that sticks into the tank on the Fluval. Fits like a glove - no rubber band or string needed. Not the best looking - but it really works! It's soft enough that I don't think it will hurt the fish.