Mentos geyser at the park

I promised the kids that we would do a Mentos experiment all summer long.  It is the last day of summer for the kids and they go back to school tomorrow, so I took them to Rasmussen Park.  I bought 3- 2 Liters of Diet Coke, and 3 packages of Mentos.  Apparently diet soda makes a larger geyser.  We dropped the Mentos into the soda and there was a HUGE geyser that shot up 20 feet.  The kids got to do one each and had a blast.  It was a great experiment.  Afterwards, the kids played at the park.