I have been working hard on my drainage trays. I built 13 trays this weekend at Whitehawk, got them primed, and got a few of them painted green (until I ran out of paint). Cutting the PVC plastic with a table saw and chop saw works great, but makes a terrible mess. There is plastic all over the garage. I also installed three of the trays. One on the top shelf where it completed the top drainage system, and two on the bottom (shown here with plumbing). They work well.
There is perhaps too much water in these trays. I will have to test them out. I can always put a 1/4″ insert into the trays to raise the gravel level slightly.
When finished, I will be able to water the plants in place. Should be much better for the plants, and save me quite a bit of time.