potassium (potash) deficiency - (the last number in your ferts percentages) - you can use wood ashes and water, for fast fix, however, it's not really critical - (tends to be more cosmetic than anything) - your leaves yellow and die during later flower stages, the plant is dying, and throwing all its energy into flowering, for survival - and, as Stinky said, your pH is too acidic - :jointsmile: