Building a Volcano With Stream & Pond

This is my DH's latest pond building project, which he hopes to finish in a few days. He'll build a volcano (lava rock & fogger) around the tub at the top, and a flow of lava (red-colored water) will flow down the stream into the pond. Black lava rock (cooled lava) will surround the stream and pond, and red lava rock (still hot lava, but beginning to cool a bit) will be in the streamlet sections.