just to add, pre-packaged PH up and PH down solutions are designed for hydrophonics, and should be used very carefully in soil or hydro.

if you take PH to far in either way, you are better off scrapping the soil and starting over. in other words, you should never use PH down to compensate for adding too much PH up and vice-versa.

your better using a "softer" natural ph adjuster added to the water slowly over time.