OH! This so reminds me of my Betta/ghost shrimp nano i got going. i am using a Red Sea hang on back filter with a dried up kitchen sponge between it and the outside of vase to keep it at a steady/level intake. It can totally work. you would just have to change water about once a week/every two weeks. I should put up some pics, just gotta take them. yours is a little narrower than mine but i practically got goosebumps just looking at your pic. keep it up!!!!