Don't put them with any fish like tangs or angels that may nip at them thinking they are macroalgae (which shouldn't be an issue in this type tank). They are very picky about food, but live ghost shrimp gut loaded work well, and if you can get them to take frozen thawed off a pair of forceps, even better. Mine took about 3 months before he'd take food off tongs, before that I just dropped them in by him one at a time. You can always start a small freshwater tank to breed guppies or mollies as well, and then you have a clean source of gutloaded live feeders that won't cause thiaminase issues. And avoid krill to prevent lockjaw. Keep up with the water changes, and the live macroalgae will help as well. These guys produce a lot of waste for their small size.
And if you're keeping this fish by itself, this is one of the few species I'd skip quarantine for. I would still treat it with prazi to deworm and de-fluke it, but it should otherwise be good to go.