@Path of Light I love how you're jumping in and giving solid advice. This is what I think Rollitup is all about, people helping people.
@Bron-Y-Aur Stomp a PH meter is an absolute must in any grow. You can do any form; digital meter, test strips, testing solution (which is my prefered method). PPM tolerance varies by strain, so my feelings are as long as the little ones look happy and I'm regularly changing & cleaning reservoir. I won't be too picky on PPM. Everything in life is learned through experience, and we choose Hydroponics. Good luck with the growing.
-Shifty