Acquired: Online breeder / seller,
Breed species myself,
Fish / pet store,
Worked with fish (didn’t own)
Portland, California, United States
Posted Nov 21, 2015
Koi really are great for for ponds and only great for ponds. They get over 3 feet long and live up to 90 years. For this reason trying to keep them in tanks in not ideal. Mine even quickly outgrew the small pond I had and needed to be relocated within a year. It's a myth that fish will only grow to the size of their environment. If you think about it how silly would it be to say "kids only grow the size of the house they grew up in". I guess Lebron James grew up in a mansion then.
Koi are very easy to feed and will eat almost anything. If you want them to have nice bright colors and grow faster then you will want to vary their diet. Mine ate "miracle Koi Food" which a blend of large and small pellets with freeze dried krill. I also supplemented with peas, watermelon, and mandarin oranges. They will also graze on algae.
Koi should have at least 1,000 gallons per fish unless you want to continually upgrade or trade away fish. Upside koi get along well with goldfish (like wakins comets) and shubunkins that stay smaller. So you can have one or two large prize koi and many smaller shubunkins for a busy pond that isn't overloaded.
My koi got along with the fantail goldfish, wakins, shubunkins, and mosquito fish in my small pond. I also kept large pond snails that did well.
My fish also bred in my pond and I didn't do anything special as far as I know. Come spring it just happened. Diet might play a role, again having high protein and being varied. During breeding season is the only time you can sex your fish otherwise they all look the same. Males will get white spots on their gills and lining their front fins while females make no change at all other than they may get a little bigger. If you have both males and females, good water quality, and good food they will just lay eggs in the pond and you will have fry swimming around. Fry are fragile though and need food, and hiding places. I took a batch of eggs on a leaf and raised them inside where they couldn't get sucked into the filter, eaten, or starve. I fed them flake, baby brine and seaweed. It took about 6 months but eventually they were big enough to add to the pond.