How to Build a Koi Fish Pond. Koi and other goldfish can grow very large, sometimes reaching lengths of over ! They're best housed in large ponds with a TON of filtration and weekly water changes. With the right size pond, filter and other.
This advice is intended for anyone installing a small (under 1000 gallons - about the size of hot tub or less) prefab garden pond or other little container pond on a patio or balcony. Ive had several different types of ponds over the years, and,