hmmm, fair play, but they recommend putting twice as much feed in also, so I'll take it with a pinch of salt and feed them what they need, not what canna say, all i can say is that my last 5 or so grows, i have not altered the ph with acid or anything else (really cant remember where i heard canna self buffers, but i stopped ajusting after that)
After just reading the canna bag itself, it too says that you gotta put in water @ 5.8...hmmm, well, i aint changing what is already working perfect for me, but it does make you think...does it really matter?