My backyard overhaul journal

[kien]

Originally Posted by Dez

They stay outside all winter. Most people that I've talked to that have tried wintering indoors and outdoors prefer leaving the fish outside. Keeping large fish indoors requires tons of water changes just to keep the water quality high. With wintering them indoors, you have to feed them which soils the water.

When I first started I used to winter my koi inside too. Did that for a couple of seasons until I couldn't take it anymore! You need a very large container, lots of water changes, etc. It was a royal pain in the butt. After doing more research and discovering that people overwintered their koi outside I went that approach as well and haven't looked back. Any ya, it always surprises people whenever I tell them that the fish stay outside all winter. Genetically koi are a cold water fish. They will hibernate just like any other lake fish.