Demo Idea: Clear Spheres!

Title:
Clear Spheres aka Jelly Marbles aka Water balls
Source:
http://www.stevespanglerscience.com/product/clear-spheres-kit
Target Age:
Kindergarten and up (while they can be enjoyed at any age, they might be dangerous to really young kids)
Materials Required:
flasks, water, clear sphere pellets, big bin with water, clear glass brownie pan, paper w/ MAS logo
Prep Time Required:
Need at least 3 hours in advance to let the balls grow
Demo Time Required:
the demo itself will probably take about 5 minutes with the reveal and explanation, but the people we are showing them to should be given ample time to play with them :o)
Description:
We have 2 identical flasks, one with plain water, one filled with water and water balls. We ask the viewers of our demo if they notice anything about either flask. We have a volunteer first stick his hand into the flask with just water, and then have them stick their hand in the flask with the water balls in them and be surprised. We explain that the water balls are made of this special polymer, or chain of molecules, that are super-absorbent. We show them a dry pellet, and a fully-grown water ball and tell them that the pellets absorb water up to 300x it's original size. We also say that they look invisible in water because they refract the same amount of light as water does, which means that our eye perceives these water balls to look the same as water does. We show them the clear glass brownie pan that has nothing but water balls in it. The brownie pan is sitting on top of a picture of the MAS logo, which looks jumbled. We ask a volunteer to pour water in and the crowd to unscramble the message. See the video below for more experiment ideas!