I see that you got your answer already, but I make my own water gel too. I purchased a pound of the crystals for $10 with free shipping and 1 pound of the crystals is able to make 16 gallons of water gel. I use distilled water or RO, I toss a teaspoon of the Crystals into a Rubbermaid 4 cup container, fill the container with water and watch the crystals grow.
PM me if you would like to know where I purchased the crystals from. The free shipping is only available in the US and online they accept Paypal only. I had to call my order in because of my location.