Geyser Tube

Price: $8.95

What started as a classroom science experiment quickly turned into a world-wide internet sensation. Learn how to trigger an enormous geyser by dropping MENTOS chewy mints into a bottle of diet Coke using the Geyser Tube. The eruption is amazing . . . and so is the learning if you consider the science behind the fizz.

Age: 8 +

What you get

Steve Splangler’s Geyser Tube carded. Mentos not included. The easiest way to get the diet coke and Mentos experiment to work.

How does it work?

Each Mentos chewy mint has thousands of tiny pits all over the surface. These tiny pits are called nucleation sites – perfect places for carbon dioxide bubbles already in the soda to form. As soon as the Mentos hit the soda, bubbles form all over the chewy mints and then quickly rise to the surface of the liquid. Couple this with the fact that the Mentos are heavy and sink to the bottom of the bottle and you’ve got a double-whammy. When all this gas is released, it literally pushes all the liquid up and out of the bottle in an incredible soda blast. That’s the simple explanation. Want to know the rest of the story? Visit www. to learn more about the science behind the Geyser Tube experiment.


  • Carbon dioxide gas
  • Saturated solutions
  • Gas pressure
  • Nucleation


Will I get wet?
There is a possibility but the geyser tube device is designed to minimize the likelihood of getting wet, especially with the 3-foot long string.

Is it reusable?  
Yes, all you need to do the experiment again is another pack of Mentos and a new bottle of Diet Coke.

How high does it shoot?  
It all depends on the bottle of Diet Coke; a new bottle works better than one that has been sitting around for a while.  On average though, it shoots to a little over 6 meters. Huge!

What type of soda works best?
We have experimented with all types of soda and the soda that gave us the best results was Diet Coke due to having the most carbonation.  However, any soda or carbonated beverage will work.

Does it hold the entire roll?
No, the maximum that the tube holds is 11.  The roll is 14 so you can snack on the other three!!  We found that 7-10 Mentos produces the highest Geyser.

CAUTION: Keep soda out of eyes.

WARNING: CHOKING HAZARD – Small Parts. Not for children under 3 years.

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