I came across the forum when I was searching "live mealworms for koi" in google. I am new to this particular hobby but keeping aquarium fish for long. I have a small heated koi pond 12 ft X 7 ft X 5 ft high which was built in Jan 2015 and fish was introduced in April 2015. I also covered the pond during the last winter. I have 10 Koi of varying size, all growing, the largest is about 14 inch and the smallest being 10 inch. I only feed koi food from market. But started feeding some earth worms recently as a treat. I keep an eye on the water parameters and change about 10% each week. Thanks.