How Does Steve Spangler's Geyser Tube Work?

Coke, Science, Physics, Steve Spangler
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Level Up Your Diet Coke & Mentos Game

The Geyser Tube by Steve Spangler is a small piece of equipment that you screw on to the top of your Coke bottle that not only makes the experiment easier to do but improves it. But how you ask? Well, in this post, we look at how the Steve Spangler Geyser Tube works.

Parts of the Geyser Tube

Before you can understand how it works, you need to quickly look at the parts and design of the Geyser Tube. The image below shows the two main parts of the Geyser Tube in addition to the main body itself.

The Release Mechanism

The release mechanism is at the base of the Geyser Tube. It holds the Mentos in place and allows you to deploy the Mentos when you are ready easily.

The Flow Restricting Nozzle

The nozzle is at the top of the Geyser Tube. It unscrews to allow you to insert the mentos, and once screwed in place; it acts as a nozzle to increase the height of the Coke Geyser.

How the Coke Geyser Tube Works

How To Use The Geyser Tube

To use the Geyser Tube by Steve Spangler, you follow these simple steps:

1: Screw entire tube onto a full bottle of Diet Coke.
2: Remove the Nozzle from the top of the Geyser Tube.
3: Ensure the Release Mechanism is pushed in fully (Very Important).
4: Place mentos into the tube.
5: Screw Nozzle back onto the top of the Geyser Tube.
6: Pull Release Mechanism when ready to deploy Mentos.

How Does the Geyser Tube Work

The Geyser Tube has two essential functions that will improve the Diet Coke & Mentos experiment drastically.

The Release Mechanism

The release mech on the Geyser Tube allows you to deploy the Mentos into the Diet Coke easily. Without it, you will have to find another way to keep all the mentos together and put them into the bottle as fast as you can. I have seen this experiment fail many times due to Mentos Deployment. This mechanism is simple and valuable.

The Nozzle

The nozzle at the top of the Geyser Tube has a smaller opening than the Coke bottle itself, so the height of the spurt of Coke will be a lot higher than if you didn't use the Geyser Tube. Thus turning the ordinary Diet Coke & Mentos Experiment into something amazing.

The amount of science that is going on with this nozzle is crazy. I am not an expert in fluid dynamics; in fact, I am not an expert in anything. But I have done some research, and here is a simple explanation:

The reaction between Diet Coke & Mentos causes a certain amount of fizz and spurts out a certain amount of Coke in a certain amount of Coke. Let's say it spurts out 1 litre in 5 seconds for convenience sake. To get 1L out of a regular bottle (Without the Geyser), the Coke has to flow quite quickly, which creates a spurt of Coke. Now, if we make the opening smaller by adding the Geyser Tube, the same amount of Coke (1L) has to spurt out in the same amount of time, but because the hole is smaller, it has to travel faster. The faster moving Coke creates a higher spurt of Coke.

This effect isn't much different from putting your finger over the end of a garden hose. We have all done that, and we know the water sprays further. Here is what an expert says is going on when asked: Why is it that when you put your finger over the tip of a hose, the water shoots out farther?

The answer centers on the idea of matter conservation. If a certain amount of water flows into the hose from the spigot, that water must either flow out of the hose at the other end, or accumulate inside the hose itself. Since a garden hose is made of stiff plastic (generally), it won't expand to let more water accumulate, so the water must eventually flow out of the end of the hose. When you put your finger over the tip of the hose, you decrease the amount of space the water has to flow through. Since the same amount of water has to flow out of the hose before and after you place you finger over the end, the water must shoot out faster (to keep the amount of water flowing out a constant). And, thus, since the water shoots out faster, it travels farther.

Answered by: Andreas Birkedal-Hansen, M.A., Physics Grad Student, UC Berkeley
Source: PhysLink, Ask an Expert

Diet Coke & Mentos With & Without the Geyser Tube

The Steve Spangler Geyser Tube, without a doubt, makes the Diet Coke & Mentos experiment easier and better. Here are some video examples of the experiment with and without the Geyser Tube so you can see the difference for yourself.

Without the Geyser Tube

Here are a couple of videos showing off this awesome experiment, but without using the Steve Spangler Geyser Tube. They certainly got a reaction, but it does highlight the advantages of the Geyser Tube.

Diet Coke and Mentos 2!!!
These young guys look like they are having a blast with the Diet Coke & Mentos experiment. They did it perfectly but without the Geyser Tube.


Diet Coke and Mentos explosion
A fun video of a Dad and kids trying the Diet Coke & Mentos Experiment without the Geyser Tube. This one highlights the need for a Mentos deploying mechanism.


With the Geyser Tube

Here are a couple of videos, including our example of the Diet Coke & Mentos experiment using the Geyser Tube.

Testing Out the Steve Spangler Geyser Tube
This is our recent video. Showing the advantages of the Geyser Tube and a video of it exploding.


The Volcano Experiment (aka Diet Coke and Mentos Experiment)
This is an entertaining video and is a comparison video on its own. They first experiment traditionally, and then with the Geyser Tube.


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