Cool! I share the worry about it looking less clean in a few weeks. I wonder what it would look like if you were to frost the planters and put a small LED underneath them that shines up.

If you like the shiny exterior of the glass, you could also put a smaller diameter matte black planter (so there's a 1/2 inch gap to the glass) into the first one. Maybe both could contain water? I wonder if that would give you a tell for when to water the plants as well...