Wow!!!!!!!!!! fantastic, I have no words for this, it's completly out of this planet, are you using natural rocks or builted rocks, I can see those rocks are natural but I have my doubts, rocks are totally miniature islands, I can see water is real but in some works I can see is something like acrilic right????, thank you for sharing!
They're expensive I'm sure........try a local granite countertop business for scraps of granite and or marble......that is what I have done, except I don't carve them out, which would be awesome. Just don't have the tools.
I'm wondering if those Penjing trays are hand made (as are many of the 'rocks') out of cement .. surf the net a bit more and search for (something like) 'make your own cement pots' and I think you'll see what I mean
If you are asking why water does not overflow then the answer is it's a close loop system. They use tiny water pumps to pump up the water from the reservoir and run down the water like a waterfall continuously. If you look closely, you'd see that there are electrical cables behind some of them to power the pumps.