Copper is an immobile nutrient that is essential for chlorophyll production, enzyme function, respiration, lignin synthesis, and stress tolerance. A deficiency of copper can occur due to high levels of pH (>7), excessive nitrogen or phosphorus levels, or root damage. A deficiency of copper causes the new growth to turn pale green or yellow with twisted or curled tips. The plant may also have reduced branching, bud formation, resin production, and aroma. To fix a copper deficiency during flowering you should: Flush the growing medium with pH-balanced water to remove any excess nutrients or salts that may be interfering with copper uptake. Apply a balanced fertilizer with micronutrients that contain copper at half-strength according to the manufacturer's instructions. Adjust the pH of the water and soil to 6-7 for soil or 5.5-6.5 for hydroponics to ensure optimal copper availability. Avoid overwatering or underwatering the plant as this can affect the root health and nutrient absorption. Monitor the plant for signs of improvement or worsening of the deficiency and adjust the fertilizer dosage accordingly.