For sale
GreyWater.com
It is the actual technical term, not a brand approximating one. Regulated fields notice that.
Water reuse is a field where using the real word is worth more than inventing one.
The opportunity
Water restrictions are arriving in places that never had them, and reuse is the only supply nobody has to go and find. Greywater can be the name on it — a systems manufacturer, an installer network, or the standard a regulator points at.