Hey, ya you could split it in half that's how mine is setup. I have a piece of plexi glass as the divider, I have heard of people getting small leaks were the caulking from the tank meets the new but I haven't had any problems and its been about 9 months. And if you have a fish store close by you could pickup the caulking there and do it yourself instead of paying someone else to do it. For the filter that tetra is what I use, again if you have a fish store I imagine if you explain to them the small amount of water you need to be filtered someone there should be able to help out. unfortunately I don't know the most myself about them and I don't know what is available to you, even a small turtle filter would work if you could find one of those. If you do the caulking yourself give 48 hrs to set and let the fumes dissipate before putting anything back in. I will try to post a picture in abit of mine.