@Ken hi what a lovely tank, I would stock it with 6-8 danios like of a zebra or leopard variety, I recommend these fish because in my experience they like a twenty long because it gives them the room to swim. I would not get these if you don’t want something fast or flashy, since danios want to dart around and some when the light hits them can actually “flashy.” If this tank is in the living room that can be really cool but places like in your bedroom can be really annoying. Best of luck, please upload pictures when it’s done!