PH drainage at 4.70? why

I'm useing Miracle grow moisture controll (which I hate to use, long story though)any ways. I'm just giving them water of PH 6.8, but I tested the water that drained out the bottom of my pot and it measured 4.70!!!!! Why, when I'm giving it PH safe water???

I'm not sure, but its hard to believe that noone on this site does no, this site is full noobs, not enuff pros..

because your soil is acidic if you are putting it in at 6.5 and it's coming out at 4 then you need to raise the ph of your soil, by adding things such as lime to it via it's feed.