well splotches usually indicate that there is a nutrient problem ethier to much or too little and since it is in 4th week of flowering it could be a phosphorus deficiency
growhand420 Reviewed by growhand420 on . 4weeks into flowering and startd to see light green patchs on top leafs. 4weeks into flowering and atarted to see light green patchs on my top leafs, Rating: 5