Question:
I know everyone recommends using distilled water in a humidifying device,but...

Can reverse osmosis water be used as well? The RO process supposedlyremoves all chemicals and minerals from the water.

Answer: Reverse osmosis is a very good method to remove harmful compounds from thetapwater. In this process water is filtered through an ultra fine membraneat a pressure that is higher than the osmotic pressure. The membrane keepsback most of the organic and inorganic compounds dissolved in the water, butallows the water molecules to pass. A reverse osmosis system thus removes(except for a very small amount that remains) all unwanted substances likenitrate, phosphate, silicate, aluminum, copper, arsenic, asbestos, atrazine(herbicides/pesticides), lead, mercury, etc. The amount left behind in onthe order of 20 ppm TDS and is acidic (pH of ~6). It is generally acceptedthat porosity of the membrane is very tight with holes (if you want to callthem that) of 5 to 20 angstroms (.00000002 inches in diameter). Themembranes are several mils thick with most consisting of an asymmetric layer(active membrane) with the balance a more porous substrate, spongy in naturethat serves as the support for the asymmetric portion.

The quality of the water is so pure that it is used in photographychemicals, kidney dialysis, humidification, battery water, hermodialysis,and various biomedical and laboratory applications. Rest assured, thiswater is good stuff. At a price of (MAX) NINE cents per gallon (thatincludes maintenance and water costs), it would be cost effective if youwere to purchase an RO unit to also use as an everyday drinking watersource. Home distillers OTOH are a waste of money and can be potentiallydangerous as rust in a major problem in those systems.