Gray water is a generic word to water which were is use already, but can be re used for second needs. In contrary to the term black water, which is the toilet water and needs special treatment, Gray water can be easily recycled and re used for second needs.
Water from the sinks, shower, washing machine etc, are Gray water and after short and easy treatment, they can be re used as Gray water for gardening, washing and toilet flush water.
Reusing Gray water is pure water saving since with no fresh water, we are able to complete the daily needs. Instead of using fresh water for the garden, we are using water which supposed to go to trash already. Toilet flush water can be with soap ( even better ), therefore using the shower water for this cause is a great idea.
Western man is using more than 60 liters of water that can be gray water. It means that per person, 60 liters can be saved a day if he will use the gray water wisely and have the system and pipes to do so.
Either by gray water system or by pirate system each can build at home, the water saving is huge and the potential to re use water is even bigger. For the personal best of saving water and saving money, for the best of the ecological systems and water sources, re use gray water.