Since I keep my plants in the living room, I wanted some shelves that look somewhat nice. So I have a pair of Ikea LERBERG metal shelves. I have mostly small and compact growing orchids, so somewhat limited shelf height isn't an issue. The few large plants I have aren't on the shelves.
__________________ Camille
Completely orchid obsessed and loving every minute of it....
I have similar shelving that when we move again I plan on setting up again. But I don't use the plexi on the shelves, I went out and bought large baking sheets and filled them with aquarium gravel then filled them with water to help a smidge with humidity. I then put the pots with dishes under them so the roots don't touch the rocks. Worked really well. Here's an old photo, sadly don't have many of these orchids any more, but you get the idea of the setup.
Just to give you some ideas, I got my plant stand from Gardeners Supply. Mine is a 2-tier stand with 3 T5 HO on each shelf. They also offer a 3-tier plant stand. It was kinda expensive, but it was exactly what i was looking for. Here's a picture from the website: