Date: Fri, 28 Mar 1997 13:20:27 -0800 (PST) From: Matthew Baggott <mbagg@itsa.ucsf.edu> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1175$foo@default> Subject: Re: Acid Rain (And Re: Fluorescent lights)
The question of acid rain's effects on CPs should probably be split
into two separate questions: whether acid rain harms CPs growing in the
wild and whether acid rain will harm CPs in cultivation.
As I understand it, ecosystems such as bogs are able to absorb a certain
amount of acid rain without a change in the water's pH. This ability
varies from ecosystem to ecosystem. Therefore, aside from any primary
damage from direct rainfall, I wouldn't expect CPs to be
particularly susceptible to acid rain unless it has reached the point
where it is seriously damaging the whole bog (probably the bacteria
would be affected first and would "domino" out to other organisms).
I don't think this means that we can use highly acidic rain water on our
plants with impunity. CPs "in captivity" don't have a large bog to
stabilize their environment. A little drop in pH probably won't harm the
plants, but one of the important ways that acid rain damages organisms
is by increasing the solubility of compounds in the water. For example,
heavy metals in soil which are normally pretty insoluble become soluble
when the pH drops. These metals, in turn, can interfere with
biological processes in plants (and other organisms) by doing direct
damage and reducing the availability of other necessary elements. If
you're getting your water straight from the sky, maybe this wouldn't be
much of a problem, but I would be concerned about rain water that is
runoff from a drain system. Personally, I would test the pH of the
rain water before using it. Of course, this is just my opinion and I
have no particular expertise in the area.
There had been some discussion of using tap water on CPs and it had
been pointed out that the water company should have useful data on the
purity of their water. (Of course, they can't really tell you if
lead solder in your house's pipes is getting into your water.) Although
I've never done it, an additional alternative might be to have the water
tested. I've seen companies which sell water filters offer to test your
water cheaply. Since these companies are hardly disinterested, I would
probably use a "control" solution of distilled water possibly with a known
amount of salt dissolved into it in addition to my actual sample. Just an
idea.
Personally, I'm using tap water filtered through a brita filter
mixed with distilled water (when I'm feeling rich).
Now for my question on lights:
I am interested in what people who grow CPs under fluorescents do about
replacing light bulbs. The most recent issue of Organic Gardening
magazine mentioned that, after a few months of use, the lights become
much less bright. It never occurred to me to replace lights before
they burn out (it seems expensive and environmentally wasteful), but
I am concerned that the n. ventricosa and s. purpurea in my tank
aren't getting enough light. Therefore, I am considered replacing the
(still working) light bulbs. Is this foolish?
Matthew Baggott, mbagg@itsa.ucsf.edu
Research Associate, Drug Dependence Research Center
University of California, San Francisco
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