Ph Question

hey fellow stoners , im currenly growing red cherry berry in a stealth dwc pc server case. ive got it set up but i got a ph meter pen with only ph 7 buffer,i need to know if i cud use vinager to calibrate the ph 4 but vinager is ph 3,any help much appreciated,btw will be making a grow thread with pics soon,thxs

you want ph to be between 5.8 and 6.4, i don't know about vinegar, haven't heard it used before. Most people, I'd say, go with an actual ph down solution, or H2O2 (Hydrogen Peroxide)

thanks, heres a pic inside my case, i have a 150w veg cfl, a 220w flowering cfl and a co2 unit