^ told ya so :/ LOL!!!!!!!!! clowns can hold their own, you really could do anything suitable for a nano tank. I've had clowns in with gobies, blennies, Basslets, wrasse and pipefish. Clowns can be mean so I wouldn't suggest a helfrichi firefish, pipefish or any fish that can't really fight back (learned the hard way thankfully I had two tanks lol). To be honest with a tank that size I would stick with a shrimp & goby, maybe a sixline or Mccoskers wrasse or possible some sort of basslet (yellow assesors are very cool!). the only fish you should stay away from is clowns, as mentioned above damsels and fish too big for your system. I would agree with adding them a couple weeks apart. Good luck.