You can build your own ignition device for the famous Mentos and diet soda geyser eruption.
Steve Spangler Science has been performing and explaining the Mentos® Soda Geyser for years. So many geysers have erupted, in fact, that a device was designed to streamline the process. The Geyser Tube™ is, hands-down, the very best way to ignite a soda geyser that can erupt 15 feet (4.5 m) – or more – into the air. Of course, you may want to experience a soda eruption right away so here’s how to create a Homemade Geyser Tube using stuff you probably have at home.