Start of a new growing season

I learned a lot last year on using the Autopots hydroponics system. One of the challenges I want to find a solution to is standing water in the pots after a heavy rain. The basins need a way to drain.

Yesterday, I went to the hardware store and picked up a spigot, but after looking at the depth of the basin, I don't think it's going to work. I'll have some time to figure this out while the plants are still small. I'll be able to remove the plants from the water basins for several weeks (until the plants get too big).