Kit's water: RO vs. SD

From: Chuck Rossi (chuckr@vmware.com)
Date: Mon May 08 2000 - 16:18:55 PDT


Date: Mon, 8 May 2000 16:18:55 -0700
From: Chuck Rossi <chuckr@vmware.com>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg1443$foo@default>
Subject: Kit's water: RO vs. SD

I'll just add my experience here, as I've recently gone through the whole RO
vs. steam distiller (SD) evaluation....please skip this if you've seen the
"what water should I use" discussion a million times already......sorry
for the length.

After growing CPs for a little over a year, I eventually realized that with
even a small CP collection of 10 or 20 plants, it might be cost effective to
get a water system rather then pay US $1.00 a gallon for RO distilled
water...especially here in N. California where there is basically no humidity
in spring and summer and water evaporates like crazy.

I looked through the CP list archives searching for distilled water info, and
found that most people seemed to talk about RO more then steam distiller
systems. So with that in mind, I set out to find a system to buy.

Searching the web for water purification isn't fun. There is plenty of BS and
snake oil to wade through. Here's what I found:

RO Units:

o For the large scale or commercial grower, RO systems are the way to go.
   They can process more water and are more of an "on demand" system.

o RO systems tend to be more complicated to install and maintain. Some use
   pumps and need a power source. Most all need some basic plumbing work to
   install.

o RO systems need filter replacement at various intervals (varying from about
   3 months to 1 year, depending on conditions and type of filter).
   Replacement filters aren't very cheap (US $30-$50 for a low end model).

o RO systems are more convenient in that you have a faucet, you turn it on,
   and you get pure water.

o Price ranges are from US $150 - $thousands.

Steam distillers:

o Steam distillers are BIG, UGLY, and expensive. The exceptions to the
rule
   are the smaller "coutertop" units that look like automatic coffee
   makers. They are still a little big, kind of ugly, but not so
   expensive. It really is impressive how ugly the big systems are.

o The big, ugly units have the convenience of the RO units - you get
water
   from a spigot when you want it. The cheaper tabletop units are more
   of a pain, as you have to collect the water in a jug, transfer the
   water to another container, clean and re-fill the boiler, then make
   more water.

o SDs usually have some sort of charcoal 'post-processing' unit that must be
   replaced at 3 to 6 month intervals. They are usually pretty cheap.

o SDs need to be cleaned periodically to remove the nasty scale and
burnt gunk
   left over from the distilling process.

o SDs are s-l-o-w. The larger units get around this by acting like hot water
   heaters, and keep reserves stored up in tanks of various sizes.

o SDs all need a power source. Most SDs have a fan. The fan can be loud.

o SDs supposedly make "more pure" water. The reasoning: By turning
water
   into steam, the heavier than steam contaminates are left behind or
   killed. The SD crowd feels that the RO system can be compromised by
   dirty filters. This isn't so much of an issue for CPs, but something
   to consider if you're thinking of using this water for your
   household. Even then, it's probably not too much of an issue.

o Price ranges are from US $90 - $thousands.

For the "small time" grower, the options boil down (heh) to this:

Buy it locally or from CP sources. The web based water stores all seem to be
very overpriced and of varying quality - both the products and the "stores"
themselves.

Your low-end choices:

o SD: The Sears Kenmore Countertop Water Purifier (#625.34440) made by
   Eco-water in Japan. List price of US $130, on sale for US $89.
   Takes about 5-6 hours to make one gallon. Very "hands-on" as far as
   filling, cleaning, and transferring water.

o RO: 3 cartridge "under sink" system as offered by California
Carnivores and
   other CP stores. Prices from about US $150 - $200. Can produce 8 -
   12 gallons a day. Very convenient, once installed.

I finally went with the Sears/Eco-water system - the one David Ahrens
mentions. It is the most prevalent table top still, and for US growers,
the easiest/cheapest to obtain. If you maintain a smaller collection,
you should be able to keep up with your water needs, plus use it for the
household and not have to buy bottled drinking water. In the end,
depending on how much your electricity is per Kw/h, you'll be saving a
little money.

Chuckr



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