KFG: I have a somewhat different but serious comment. I took my whole family to visit Quality Koi Farm last Saturday in NJ about 30 miles south of where I live. They have an indoor tank for their females. Its about 50 ft X 100 ft X5 ft [ i am not that good with measurements] with about 50 large females 10-30 lbs. They are fed every hour and they installed an incredible bio system for waste processing. They really treat these females well. The largest is an Ochiba at least 30 lbs.
If you get time, my suggestion is taht before you start breeding, visit this farm. Quality Koi people (Matt, Ross etc.) are very nice and they take their time to show you around. I think you will get a first hand look of an excellent breeding program. It might help you to breed your brood well.