I wrapped the pump cage with the double layer of cheese cloth just before dark, about 84 hours (3.5 days) after the spawning. I checked the record of the last few seasons and then estimated that at these temperatures, hatching may be at around 4.5 days. I considered waiting until tomorrow morning so that the cheese cloth would last longer past hatching, but I figured that would be cutting it too close.
Most of the spawns have had water around 70 F (upper 60's to lower 70's) during the period between spawning and hatching. In those 5 seasons, hatching occurred 50-60 hours. In two of the seasons, water temps stayed in the lower 60's down to about 60 F, and hatching took ~4.5 days. So since the temps this year have been 60-63 F, there may be hatching sometime tomorrow afternoon or night.
I usually just move the one female and 2-3 males to the spawning tub at the same time. This is the first time I've only included one male, since he is a bit larger than her. I don't do anything to condition them for spawning. They almost always need some type of spawning material to get going, but I think one spawning rope would get them going as well as ten. I just put in extras to get them to disperse the eggs more to improve oxygen to the eggs and thus improve hatch rate.
Getting them to spawn can be tricky. Sometimes it happens on the first night. Sometimes it takes a week. Sometimes they won't go at all. But change seems to be a frequent driver, whether it's the first night in the new spawning tub or pond, a storm front, or a water change. My wife also has a theory that spawning may be more likely on days when fishing is good. She checked the Farmer's Almanac and found some correlation between the days the spawns have occurred and the best fishing days.
I've heard some put a light over the pond at night, but I have not tried it. Other's say the full moon is best, but I've never noticed much correlation with that myself.
I have on occasion misidentified a male as a female and vice versa, and found it true that you need one of each.
Also, some koi behave differently than others. Once I had a group of three males and a female (properly identified) that wouldn't spawn. After several days of nothing, I added a second female, thinking the males might like her better. It worked! But not the way I intended. Not only was the koi not female, but he was far more aggressive at spawning than the other males. His instigating behavior got the original female going, and then they all joined in. Whatever works, I suppose!