i was wondering what to feed a koi fish i have on in an aquarium i have 4 to put him in as he grows til he big enuff for a pond,but rite now he just a little thing bout 3 inches.what do you feed them to have a healthy koi rite now i feed him gold fish pellets.the girl at the pet store gave me a 5lb bag of pond food i dont think that rite for a little one