The "heylloyd" idea of using just ONE tray is actually a very good idea. Thanks for bringing it up. That means paying whatever it costs for one really good tray without having to multiply that by 4 or 5 trays.
Tray rocking is the way to go with 16 X 20 and larger anyway, there's just too much damage from the usual flipping and rotating, not to mention the necessity of deeper solution, running to gallons with large prints.
I'm thinking I'll get just one really heavy tray for 20 X 24, and put in a drain tube that will drain into a gallon bucket in my dump sink that's down off the end of the big plywood sink. I was thinking a flexible car radiator hose, but better than that might be the standard 2 inch white or black plastic plumbing pipe and elbows. I'll cut a couple of rings off the ends of a molded pipe coupler, stick a piece of the pipe through a hole cut in the tray end, and use solvent weld cement to hold a ring on either side. Might have to use a heat gun to get a flat surface there though.
Then, I'll just use an elbow loose on the tube, with a short vertical pipe in it. Rotate down to drain, up to keep the chemicals in the tray. I think it will work!
Best, Todd Foster.