NEED HELP WITH PH!!!!!!!!!!!!!!!!

any acid... most people have white distilled vinegar around the house (acetic acid) 5% is fairly strong relative to the pH range we want. won't tkae more than 1-3 mL per gallon. i recommend an acid that doesn't invovled potentially available nutrinets to the plant, unless you also have some sort issue coincidentally going on too. acetic acid won't scre up any nutrient balance you have. the type of acid you choose will not affect likelihood of pH-drift. pH drift occurs from poorly buffered fertilizers if it's a soilles/hdro nute lineup, or if in soil, it should mitigate small differences in pH on its own. citric acid is another excellent choice. you'll likely have that or vinegar around without any special trip to the store. i would recommend buying some cheapie plastic pipettes. the small ones 3-5 mL ... unless you are mixing many gallons at one time, then by the bigger ones to match scale.