Mid flower flush

toward bottom starting from tips? Fairly safe to say it is a N deficiency. Don't flush, if this is the case. You flush for a reason, like an elevated EC level relative to current maturity of your plant or some major toxicity issue or something crazy out of balance, which doesn't look to be the case here. by completely dry, do you mean top 1" soil, right? Don't let the plant wilt. That's bad for its long-term health. You don't want to drastically shift pH or dissolved mierals in a short period of time -- especially in bloom. All you need to do is keep a good water-fertilizer altnating schedule and react to what the plant says.. .if it starts to get a tox, you fertilize less often or reduce concentrations (assuming it is relatively balanced for the plant, if not ratios of what you feed get involved too). I'd say you need to fertilize slightly more (or slightly increase component with most N based on picture). Always slow increments when testing new things and try to keep all other factors the same - and let it play out a bit to see full extent of change, unless overtly bad, lol. pH -- a pH near 7 would increase nitrogen availability for the plant's uses, so that is likely fine. If you've had no issues so far, i'd keep it the same. A change of pH requires a change in nutrient ratios.. if you've found a good medium, it's best to stay there.