Over the weekend my girlfriend and I divided a 10 gal. tank for our three bettas. We also decided to make it our planted tank since they weren't doing as well in the other tanks. We have pool filter sand as our gravel, it works awesome. Our bettas really seem to like their new tank. For the divider I cut a piece of plexi glass to fit the tank and then drilled holes in it for water circulation. Its so much easier to have filtration, they don't get as gross as fast.
Heres a picture:
Heres a video:

Enjoy and let us know what you think.
Heres a picture:
Heres a video:

Enjoy and let us know what you think.