This will depend on how much RO water you need. At the rate I am using
water, and at the cost of the water I can by from the local water shop, it
would take close to ten years for an RO unit to pay for itself; longer when
I set up my rain barrel, which I'd use all the time except winter. I won't
be buying an RO unit until my collection of orchids has grown substantially.
There are a couple stores here that specialize in water treatment systems
for home and small business use, plus some of the big hardware stores have a
limited selection of systems, and the specialty shops, and some of the
grocery and department stores, sell distilled and/or RO water.
Or befriend a graduate student in the life sciences or chemistry.
They have access to more RO or DI water than you can shake a stick at,
and it is free to them... However, I would suggest that a small RO unit
is not that expensive. I think I bought one several years ago which
produced much more than I could use (15-20gpd) for a little over $100.
Hooked it up to my kitchen sink with a little bit of quick connect
hardware and some ingenuity, and collected the water in a plastic trash
can. Cheap solutions are good. At my local store, distilled water is
over a dollar per gallon, so that pays for itself pretty quickly. If
you can get water for $0.10 per gallon, then perhaps it only pays for
itself in the convenience of not lugging gallon jugs of water around the
city.
I've since upgraded to a more elaborate (and correspondingly more
expensive) system, but then again I'm using RO for drinking and cooking
as well now. My new system is worth every penny. I sold the old unit
to a friend for a pittance. You might be able to find a gently used
unit on Ebay or a similar web location for cheap. Or ask around,
somebody in the local society might be giving one away. Or might let
you take a few gallons every once in a while.
Rob
--
Rob's Rules:
http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit