What makes a good pattern?

This is not something you can easily define, but one thing is balance. Balance is very important. To study this further, we strongly recommend reading Kokugyo I.

Which grows bigger, male or female koi?

After spawning, a female eats food very aggressively and gets ready for the next season. Males do not have as big of an appetite as the females. Typically, the female eats more and ends up growing bigger in girth and length.

Do koi sleep at night?

At night when there is no sun-light, Koi stop swimming actively and are quiet at the bottom. They look like they are sleeping.

When do koi spawn?

The season depends on the location. The temperature of the water triggers the spawn. In hot places like Okinawa, the season begins in March, while in Niigata it is in May and June. In tropical countries, it is possible for the Koi to spawn 2-3 times per year.