Brooklyn1 wrote:
>
> On Thu, 05 Dec 2013 13:12:57 -0500, "Pete C." >
> wrote:
>
> >
> >sf wrote:
> >>
> >> On Thu, 05 Dec 2013 10:22:02 -0500, "Pete C." >
> >> wrote:
> >>
> >> >
> >> > sf wrote:
> >> > >
> >> > > On Thu, 05 Dec 2013 08:44:07 -0500, "Pete C." >
> >> > > wrote:
> >> > >
> >> > > >
> >> > > > Ed Pawlowski wrote:
> >> > > > >
> >> > > > > On 12/3/2013 2:52 PM, Helpful person wrote:
> >> > > > >
> >> > > > > >
> >> > > > > > Unfortunately the water where I live is horrible so I am forced to use bottled,.
> >> > > > > >
> >> > > > >
> >> > > > > Either an RO system or proper filters will pay for itself over bottled.
> >> > > > > You do have choices.
> >> > > >
> >> > > > The $150 or so under counter RO systems work very well and are very easy
> >> > > > to install.
> >> > >
> >> > > What is the "waste ratio" all about and why do the lower cost units
> >> > > have a higher one?
> >> >
> >> > The reverse osmosis membrane essentially passes only clean water, which
> >> > means that the contaminants stay on the input side of the filter. This
> >> > water with concentrated contaminants generally needs to be disposed of
> >> > as "reject water" to keep the crud from building up and preventing new
> >> > water to be filtered from getting to the RO membrane. Higher end units
> >> > have better designs to allow for less reject water and thus less water
> >> > consumption.
> >> >
> >> > A key thing to keep in mind is that the under sink RO systems only
> >> > produce up to ~10 gal/day of filtered water, and the reject water is
> >> > only produced in proportion to the filtered water produced. Thus if the
> >> > ratio of reject water to filtered water is 1:3 the unit only "wastes" up
> >> > to 3.3 gal/day of water, and if you only use 1 gal of filtered water in
> >> > a day it only wastes .3 gal of reject water.
> >> >
> >> > If you are particularly frugal that reject water can be collected for
> >> > other uses such as watering non-food plants or flushing toilets or
> >> > similar where the increased concentration of contaminants won't be an
> >> > issue. This would require some work on your part to do since such
> >> > reclamation setups aren't commercially available for a small home unit.
> >>
> >> Thanks, that could be a very expensive proposition considering the
> >> cost of city water these days and how it its increasing.
> >
> >Not really, and it's an easily calculable expense. Your cost for
> >filtered water is the cost of the RO and pre filters divided by their
> >service life in gallons, plus the cost of the reject water for that many
> >gallons of filtered water. given the specifications for a particular
> >unit and the water cost it's easy to calculate the extra cost per gallon
> >of filtered water. It's likely in the range of $0.03-$0.05 per gallon.
>
> I have my own well. My _drinking_ water is prefiltered, UV treated,
> and RO filtered... it calculates to about 5¢/gallon.

Exactly, it's not a large expense. For a small under counter RO setup
it's ~$150-$200 for the unit and a low continuing cost per gallon for
the reject water and replacement filters.


> All the rest of
> the water in my house is softened, prefiltered, and UV treated, never
> had reason to cost out that water. My hose bib water is not treated,
> however I have a hose bib at the garage door that has softened and
> tempered water but I never use it... the last owner installed that
> because he was a stickler for washing his car even in frigid weather.
> I occasionally hand wash my car and occasionally it goes through a car
> wash (in cold weather when coated with road salt, there's a car wash
> not too far that even washes the undercarriage), but mostly my car
> gets washed when it rains... sometimes when there's a heavy rain I
> drive my car out of the garage, drive down the road a minute's worth
> to wash its undercarriage and then leave it in the driveway. I'm
> really not much into washing cars.