Normal practice with semi-hydroponics pots is to have two holes approximately one inch above the bottom of the pot. In talking with Chris Johnson over email, I found that he only uses one hole. He says he talked with Ray Barkalow about this, and the second hole is there in the case that the first one gets clogged. So, if one wants to unclog the holes, then one hole is OK.
Chris uses one hole as it enables him to fill the pots in his watering system better. With two holes there is too much flow out of the pot and a lot of extra water is needed to fill it to the top.
I will now start blocking one of my holes in the pot. It should enable watering the collection faster, and evidently will not make a difference.