HydroHealth uses water that has been purified twice and is of hospital grade quality. Although the colonic irrigation equipment has a built-in water sanitizing unit, HydroHealth further purifies its water supply through a U.S. manufactured Reverse Osmosis water treatment plant producing kidney dialysis grade water of the purest quality, meeting USP23 and AAMI standards.

The process of purifying the water twice is the latest technique from the U.S. in colonic irrigation. HydroHealth's water is also sampled and certified by the U.S. manufacturer and The Hong Kong Standards and Testing Centre to ensure strict compliance to U.S. medical standards.

HydroHealth is the first colon hydrotherapy centre in Hong Kong, and one of the few in the world, to use Reverse Osmosis water purification.