I started the bottom tank first, designed it to take my son's mollies. My daughter has decided she wants to add a school of dwarf corydoras and emerald dwarf rasboras. Not sure how accepting the greedy mollies will be.
Top tank was initially intended for German Blue Rams. However, my water is way too hard for them. We're talking liquid rock, and I'm not wanting to buy an RO system. So I'm thinking celestial pearl danios, some corydoras, and some other feature fish.