I have used evil tap water. (PH @ 8.0-9.5 and TDS around 250) on
orchids for short term. I still use this on most of my container house
plants. For the last two years I used only bottled distilled water on
the orchids and added small amounts of fert and PH up or down to get
it in the 6.5 range. The start of this year I set up an RO/DI 6 stage
with UV and pump (I use it for drinking, cooking, the kittys water,
and the orchids) People say that the PH swings wildly so I test
regularly and it has been very consistently in the 6 to 6.5 range
right out of the ten gallon tank. Total cost over three hundred
bucks, but I have two taps and two diff feeds upstairs and down and an
outside holding tanks with pumps for misting on the deck during the
day when it gets hot and dry. I was paying over forty bucks a month
for eight five gal. btls of distilled that I had to lug in, set up,
store and set back out for return. It has been worth every penny so
far.

Goodgrowintoyall
NANOOK

On Wed, 30 Apr 2003 11:10:22 -0400, "Ted Byers"
wrote:

So, I would suggest that you find out which source provides water to your
home. Then, determine the minimum water requirements for the plants. If
your water is too hard, you will need a reverse osmosis unit to get the
quality you need.


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.

I'd suggest you compute how much water you need to use, and from that, along
with the price per litre and the cost of a suitably sized RO unit, compute
how long it would take to pay for itself, and then decide whether you need
to buy an RO unit or just buy the water. Another consideration is whether
or not you can use rainwater. I'd assume you can take a sample somewhere
locally to have it tested (I'd be concerned about airborne contaminants).

Cheers,

Ted