The AQUS system by Watersaver Technologies is a fantastic example of green design and ingenuity. The Aqus system catches the water from your vanity basin, filters and disinfects it, and stores it until the next time you need to flush your toilet. The system then sends to stored water to your toilet cistern reducing the amount of town water necessary to simply flush your toilet. It is designed to be easily retrofitted into existing fixtures. Gravity and a small electric pump transport the water from the 21 Litre holding tank installed under the sink to your toilet cistern. A valve in the toilet cistern prevents fresh water inflow as long as sufficient water is available in the Aqus to do the job, when the Aqus runs low, the normal toilet valve for incoming water will serve the demand.
The system retails for about US$200, but unfortunately is only available in the US at the moment. Hopefully someone will look to import this to Australia because there is a definite market here for such a simple and inexpensive product.
Caroma in Australia have made a toilet suite called the Profile, see below, which achieves a similar result. But in our opinion there are significant psychological hurdles to over come with their cistern and the perception that one is washing their hands 'in the toilet cistern'.
In our opinion, the Aqus is the way to go.