Steve wrote:
I used to collect rain water in the fall and store it in gallon milk
jugs for use over the winter. They were stored about 10 feet from the
grow lights in my basement. A few of them would turn slightly green but
that did not seem to be a problem.
I stopped collecting rain water when I found out a friend had a TDS
meter. Distilled water gave a reading of zero, my rain water gave a
reading of 4 and, as I recall, my tap water gave a reading of 11. It
turns out I was wasting my time collecting rain.

Steve


I have been testing my TDS levels since I began trying to grow disas,
some eight or so years ago. My tap read 467 when I started, and the
rainwater read 11. Now they seem to have done something good to the tap
water and it runs around 210-220. The rainwater still reads 11. So I can
use the tap water whenever I need to if the rainwater runs low and save
that for the disas.

Just now I came in from the GH where I was listening to a heavy rain
beat on the roof. I enjoy the rain sounds, and the rainwater tanks are
overflowing, excess water seeping down into the gravel as designed.