Sorry

I didn't mean to be misleading. I was thinking on the lines that if you have a 45 gallon water butt that is already full (particulary on a day like today) and any extra water has nowhere to go but down the drain - where your local water company will collect it and then sell it back to you - the idea is to turn some or all of your current water into crystals and store them, leaving your water butt empty and ready to fill up again with fresh rainfall.