Clowns will eat a wide variety of foods from flakefood, prepaired frozen foods, brine shrimp, and other forms of meaty foods.
Dont be supprised if the clown does not eat for a week or so. Sometimes they go on a starvation bing when stressed by a new enviorment. Add a small amount of food daily and if it does not eat it then try to net the food out after 10 min or so.