> uses grey water for cooling.
Yes, another seemingly good idea that doesn't really work in practice.
We've had similar with RAID - remember the concept was to use large-scale redundancy to improve the reliability of cheap disks, the reality is we buy high spec disks for our disk arrays.
We're seeing the same with the idea of using used car batteries in home batteries, where it is increasingly becoming obvious it is more cost effective (for manufacturers) to use new cells in home batteries and simply scrap EoL car batteries.
In theory a gaming rig can use normal tap water for cooling, however reality means you are best advised to use special preparations using demineralised water etc. to prevent the build-up of sludge and scale. Similar with steam irons. Mine has an inbuilt scale filter, yet still needs regular descaling...
Biting the hand that feeds IT
