These tiny beads are made of a super absorbent polymer that can soak up a surprising amount of water. Plus, since they are almost entirely water when full absorbed, they have the same refraction index as water and become invisible  

Put in your plant’s soil to avoid over-watering. Create your own diapers. Fill a vase and put something in the middle to create interesting illusions. Or just enjoy the swuishiness.

This 25mL tube goes a long way. And they can be dried out and resused. These beads are clear so you can use food coloring to create any color you want.