Just cause it is done, doesn't make it right...Think about housing a Great Dane in a closet...A 10gal nano shouldn't have more than one small fish in it; like a damsel, or goby/shrimp pair, maybe a dottyback--something that stays small. Live Aquaria & most reefers here will suggest at least a 20--30gal tank for a clown. Check out the clownfish /anemone sticky on here, too.