3 Reasons to Flush:
Flushing cannabis simply involves running pure water though the soil or medium. When trying to stop a nutrient lockout or when switching nutrients, perform a flush by excessively watering your plants with water that has a pH level between 5.5-6.5 (for hydroponics) or 6.0-6.8 (for soil). Fully saturate your pots, and repeat 15 minutes later. The flush should clear any blockage and make room for your new feeding schedule.