Heidi, Some other good foods to feed, Zuchinni squash, spinach, sweet peas ( remove the outer shell) lemons, grapefruit, (actually any citrus fruit), canalope, dew mellon, and cucmbers. Be sure and remove all the seeds. seeds can be dangerous to the intestines to koi. Also a note, iceberg lettuce has virtually no nutritional value. fancy leaf, baby spinach, and romain does have nutritional value. Nibbling on the cob of the corn is not only a treat but it's excersise as well. Whole kernel corn is where the mess starts taking place.