Some people have told me I'm not supposed to keep koi with goldfish. The reason I've heard is that the slower fish can't get food.
Unfortunately, we had an issue with one of the ponds/waterfalls getting ruined in a tremendous monsoon. To prevent further problems, I must remodel it. So I moved the goldfish and koi together temporarily After a few days of the goldfish harassing the koi, and I separated them for a day, then returned them, they appear to get along peacefully. They've created small groups, where certain goldfish and certain koi area nearly always seen together.
Since I'm doing remodeling, I want to completely convert the three separate ponds into a single 36,000 gallon pond. That means they'd have to co-exist all together forever.
Is there any problem having the fish altogether? If beyond the food issue, is there a solution?
Is there some strategy for letting all fish, even slow ryukins, access to food? The food is fed by a auto-feeder.