PH?

I just read a saying to keep the PH at 5.5-5.9. Is this for soil or Hydroponic? My reason for asking is because I have a new plant and the PH is around 6.8 in soil I'm using Earth Juice ferts 400MH lights for now temp of 75-85 deg. and I'm starting to see yellow spots on the leafs probably over watering should I lower the ph some more? and if so can I gradually do this by lowering the PH in the watering water little by little every watering? "sorry for the toung twister"

U Should Add Some Pictures That Would Help ALOT

and ur PH is Fine keep the Ph between 6.0 to 7.0
like u said ur growing in soil right? then 6.8 is just fine.

About Those yellow spot i would like some pic
it could be a few thing nutes burn, heat burn ect ect
how close are the lights to ur plant

did u spray some nute on the leaves?

s
pH is a scale from 1 to 14 that measures acid-to-alkaline balance. One is the most acidic, 7 is neutral and 14 is most alkaline. Every full point change in pH signifies a 10-fold increase or decrease in acidity or alkalinity. For example, soil or water with a pH of 5 is 10 times more acid than water or soil with a pH of 6. Water with a pH of 5 is 100 times more acidic than water with a pH of 7. With a 10-fold difference between each point on the scale, accurate measurement and control is essential to a strong healthy garden.
Cannabis grows best in soil with a pH from 6.5 – 7. Within this range, marijuana can properly absorb and process available nutrients most efficiently. If the pH is too low (acidic), acid salts bind nutrients chemically, and the roots are unable to absorb them. An alkaline soil with a high pH causes nutrients to become unavailable. Toxic salt build up that limits water intake by roots also becomes a problem. Hydroponic solutions perform best in a pH range a little lower than for soil. The ideal pH range for hydroponics is from 5.8 – 6.8. Some growers run the pH at lower levels and report no problems with nutrient uptake.