Water crystals absorb up to 400 times their weight in water, and expand to make beautiful clear gel-like crystals. 1 oz. of polymer crystals will absorb up to 1 gallon of distilled water. You can even add food coloring to the water prior to adding the water crystals. The colored water will absorb in the crystals and turn them the color of the colored water.
This bag weighs 3.5 ounces (100 grams) and makes a total of 3 1/2 gallons. Make as much as you want. The crystals can be dried out and used over and over. Make sure when storing dried crystals they are NOT sealed, if sealed moisture may cause the crystals to mildew or mold.