They should be kept in a tank of at least 100 gallons as they can grow to 8 inches in length, with plenty of live rock and a sand substrate. It is a great reef fish as long as it is not kept with larger, more aggressive or speedy fish. Be sure not to house the Boxfish with cleaner type fish as well,  as it has sensitive skin, and they do secrete poison from skin glands when stressed or in danger. This poison may kill fish in the aquarium very quickly.  Also be sure to keep the lid on your tank tightly sealed to prevent jumping. They can pick on smaller inverts and tubeworms once it gets larger so plan accordingly. The Ornate Boxfish should be fed an omnivore diet of live Brine shrimp or Mysis, chopped squid, clams, mussels, and herbivore preparations for diversity in their diet.