Grey Water includes all the waste water from the house with the exception of toilet waste. (Black Water)
It can includes water from; Washing Machine, Dishwasher, Sink, Wash Basin, and Shower.
A basic grey water reuse scheme sending washing machine water using a two way diverter valve to a perforated hose will cost less than $100. A top-of-the-range system, taking all the grey water, with treatment and pumps can cost $2-4,000.
It’s available all year round whether it rains or not.
A basic system is inexpensive.
You are not supposed to use grey water on root crop plants in your veggie plots because of bacterial contamination.
You shouldn’t store grey water as it is likely to go Septic and smell.
A lot of grey water contains too many nutrients for native plants.
Many common domestic soaps are high in sodium which can cause soil problems with long term use.
Because of its disadvantages I really regard grey water as a last resort rather than a main garden watering system.
If you have a veggie plot, or a lawn, one of the more basic systems will help you in times of drought, so I wouldn’t go for one of the top of the range systems.
If you are intending to use grey water make sure you use an eco friendly laundry liquid such as Earth Choice.
A better alternative is to make sure you get the right size of rainwater tank so follow this link: Rainwater Tank Size