well thats a great question actually. Lime will only raise it to 7. anything more n you got issues. really.but to add it to every bag ive ever gotten was great actually. when they have lime you can still add some..what they do typically is they add it FOR the PH guys and sellable factors..I dont believe its got a ton of it in there and as long as you dont get carried away as it were bro,Im pretty sure youll be ok..never messed with any of my PH or soils Ive done straight outta the bag.not yet anyways lol but again Ive not used a straight bag of soil in a good long while so,just poke about n look around ,but as long as theyre not all hosed up Id say youll be fine at 1/4 cup per 1.5CF(10 gallons) bag of soil. always did me good.a lil more if there is no lime added and your not PHing water..itll work that lime out pretty soon once youve blended it well imo. if your PH ing water less should be needed but if left to buffer out hard itll need more..its pretty much that simple within organics.