Switch to plain tap water to mix your nute solution if you don't have a good reason not to.
Your humidity dips quite low, but its funny, the plants don't seem to be suffering unduly. In week 6 of flower you are nearing harvest anyway as rastaman pointed out and the signs of rootbound-ness that the plants are starting to show, and the bit of 'claw', isn't really a huge problem unless you are running a strain that takes more than 2 more weeks to finish. If it is supposed to, then I'd flush with pH adjusted tap water (check runoff to see how you need to adjust it) to clear out any extra crap in your soil and ensure that the soil pH is correct, and then immediately feed with a weak solution of your fert.
What is the NPK # on your dyna-grow? The first number should be quite low if you are feeding it in flower.