Two weeks ago I found out my pond has at least five koi fish. I have no clue as to how many fish I have. I've lived at my house for two years and did not see them until two weeks ago. We don't feed them don't clean the pond. We don't do anything for them. But my question is how can I change that with out killing them and the other type of fish in their. I would like to see a little more than two feet down before it gets mucky and can't see any thing. Its not like their small. They are at least 2 1/2 - 3 feet long. It's a big pond. We have no clue how deep it is. Its also a drain pond for the corn/bean fields.

Wow, they must be very good at hiding! That's huge!

If you can somehow get them into big containers or buckets they can stay in there for an hour or more while you empty the pond and clean it.

If you use fresh water in the pond make sure you buy a water conditioner to remove any chlorine and other nasties from the tap water.
Try to replace as much of the old water as possible.

The koi would have just been eating insects that had fallen into the water over the past few years.

They also love potted plants like water lilies in with them so they can hide away.

You are very lucky, I would love to have a koi pond, let alone on with 3 foot long koi in it! :eek: