You have water at 250 PPM, you add nutrients and get 700 PPM. How much nutrients did you add in total? Just 450 PPM. You're in the active flowering phase. Strong and rapid depletion of phosphates and nitrates sharply raises the pH. I have pure 700 PPM in veg that gets depleted just like that, and you're only giving 450 at the finishing stage. This will constantly lead to a deficiency of metals and increased pH. Remember how I advised in the last grow: bring it up to at least 1000 PPM.