Chunky old Den Phal thriving in ... gravel?!?

[Optimist]

One thing I love about gravel is that when you repot, you do not need to disturb the roots and dislodge the old gravel. All you need to do is place it in a larger pot and put more gravel around it. I have several of my plants growing in rocks, often black or red lava. When I think they need more moisture, I just put the center part of gravel inside a ring of bark, and problem solved.