Yeah, agree with above. Avoid all the crappy "Flowerhorn" foods, stick with good quality foods like hikari, and do regular water changes and you'll see a HUGE improvement in a very short period! If its a water kok, it will likely blow up abit once he's settled, otherwise like i said, good food, good water and patience. Some say showing a mirror now and again will help kok growth, but i avoided it as it stresses the fish. But it has been proven to work! Keep us updated