trying to adjust the ph of 1 gallon of plain water is a pain. you may want to use 2 or 3 gallons instead.
Bongojaz Reviewed by Bongojaz on . PH down..how much do I use? I bought some PH down, bottle does not give me directions on amount to use per gallon. My tap water is 7, looking to get down to 6. Just water for my mother plant that's in soil right now. How much PH down do I use per gallon? :) Rating: 5