I would say 12 neon tetras, a dwarf gourami, and 6 bronze cories. If you wanted to you could replace the gourami with a betta, maybe even a species that isn’t betta splendens. I know aquatic arts has gotten in 2 species that aren’t splendens and they both can be kept in groups. One was $10 each and the other was around $2 each I think.