I found a post on the site that said adding sulfur would lower ph as the soil bacteria broke it down to sulfuric acid naturally. That made me feel better about using pool down
I added a splash of white vinegar and a teaspoon of pool ph down per half gallon taking the incoming ph down to around 5.5 and the plants haven't died, in fact they seem a bit happier in that they were a bit droopy and the leaves really perked up reaching for the sun rather than curling away. The outgoing water ph is still high, about 6.8 -7 so I'll keep adding a little acid with every watering. I think I have only one pot that I may have to re-pot to save them. It is two plants in one 5 gallon pot so I may take the time to separate them as they are still in veg stage.



Thanks for the reply Headshake.
eastbaygordo Reviewed by eastbaygordo on . My PH took off and I need to adjust radically Team, My PH is over 7 approaching 8 in my outdoor soil grow. Thanks to the hints here I was able to detect and now I know why some of my ladies are yellowing. I used some vinegar as directed yet the soil is still over 7 as measured with a low end probe meter. I used my pool chemical tester to determine my tap water is near 8.0 PH and verified with probe measurement so I know where the problem arose. Are there any long lasting PH soil adjuster you recommend other than vinegar similiar Rating: 5