@Righteous Reefer Not sure to be honest I have read many grow diarys and I don't recall any one mentioning them been ph sensitive but as a rule of thumb you should ph your water between 6.0-6.8 I personally go for 6.5
Check the fox farms ocean bag should tell you the ph level of the soil try to keep it the same if you use R/O water it has less trace eliments in it which can be both good and bad are you planning on using any nutes with your grow because they also mess with the ph levels