Choices for suitable oddballs: Small eel (peacock), Black ghost knife (for a while-will need to upgrade though), Butterfly fish, puffers, badis badis, leaf fish... not really that much else oh yeah, albino sens. Upgrade to 200L and you can keep some bichirs. Anything such as a arowana, datnoid, ornate bichir, GG which count for most of the oddballs and you will need something more substantial. IMO go for a small group of butterfly fish, lazy on their own but add a few and I think they are bit more entertaining.