It is similar to a 20 gallon long. Well, it's like a 20L sliced lengthwise and set side by side. I honestly think that a couple of small schooling species would do fine, but the endler's would be good too. Maybe some otos once it is well established, but take care not to overstock it. Make sure that you have enough light to plant it heavily so the substrate is completely colonized with roots, and then (once the plants establish) you won't have to do much maintenance of the substrate which would minimize concerns about that.
Visually, since you won't have much depth, i think it would look neat to take advantage of the width and create a diagonal composition with a deep end and a shallow end (unless you are really into symmetry). The tank could look really fabulous with careful stocking and aquascaping.
Visually, since you won't have much depth, i think it would look neat to take advantage of the width and create a diagonal composition with a deep end and a shallow end (unless you are really into symmetry). The tank could look really fabulous with careful stocking and aquascaping.