Hey, cheers for the compliments. I use this Ph tester: http://www.basementlighting.com/Merc...=1/PROD/PHHEPH

It's a beauty. I had a really cheap, shitty Ph tester before that and it was phing my tap water at 7 when it was actually 9 or 10. It pays to get a decent Ph tester. I also use the Ph up and down on the same page. I don't know if the ph up and down I use counts towards the 'organicity' of my grow but there are other things you can use, like vinegar. I'm sure a search will sort you out.

I would have a guess that the runoff from your soil will be fine though. I've only ever used all mix and I've never had any problems. Even before I had a good Ph tester, I was watering with tap water at a ph of 10 and it still didn't mess up my soil ph.

However, I would do a search on how to adjust the ph of your soil because I've never had to do it. If I was to guess (always dangerous), I would do it like this:

Ok, so if your soil Ph was 5 and you wanted to raise it to 6.5, I would flush with water with a ph of 7/8+ and test the runoff until it was right. Like I said though, I'm completely guessing on this one. Still though, I'm confident that the all mix should be ok.

Edit:forgot one thing, a flush won't do the plants any harm as long as you let them dry out thoroughly before you water them again. In fact, mine always tended to have a growth spurt after a flush.