dear al,
love what your doing here.
i'm having trouble with my first grow, i'm over six weeks into flowering and have damage that is still spreading despite my best efforts.
i have two DWC 5gal buckets, GH nutrients. i have trouble keeping the pH 5.3-5.5, i can't keep pH below 7.2 for 1day.
my municipal water is bad, pH=7.5 and tds=350ppm.
day 1 (new water, let sit in a bucket for 24hr+)
i adjust pH down to 5.5, tds=500ppm. add some nutrients up to 1000+ppm.
day 2
ph=7.2 and tds=1300+ppm
adjust pH down to 5.5, tds=1700ppm
day 3
pH=7.2 and tds=1900+ppm
the tds goes very high from adding so much pH down.
after about 3-4 weeks of flowering, plants in one bucket started to get yellow spots on the top leaves, eventually turning the top of the plants very yellow and dry. the plants in my second bucket are more developed having gone 6+weeks flowering without problems but are now starting to turn yellow also.
i knew my water was a problem, i picked up a Mr Clean Autodry thing. it's a deionizer (i think), the filtered water is pH=7.2 and tds=7ppm.
with the filtered water, the same thing happens with my pH. i pH down, the next day it's 7+, i pH down again, the next day it's 7+.
with the filtered water, i can go another day or two before the tds gets above 2000ppm.
it seems like there is a buffer or something in my water making it hard to maintain acidic water.
i'd prefer not use store bought water, i'd rather buy a RO system but that may not solve my pH problem.
thanks much for reading all that.