Hi all. I have a 13.5g Fluval Evo. I have 2 clowns, 6 snails, 1 shrimp, an urchin, and several corals. I love my inverts and corals but I really would like to see someone else swimming around in there. Please give me some suggestions for something hardy, peaceful, and colorful. And no gobies, please. I don't have a top on the tank yet.