Molybdenum tends gets locked out at lower pH ranges. Your cannabis plant may show signs of a molybdenum deficiency if the pH at the roots is too low, although it is likely that molybdenum is there. That is because when the pH of your root zone is off, your cannabis cannot properly absorb molybdenum through its roots. Therefore the first step is to ensure that you have the correct pH for your growth medium

NOTE: After a molyndenum deficiency is cleared up, the problem (pink coloring and yellowing leaves) will stop appearing on other parts of the plant, usually within a week. Leaves which have been damaged by a molybdenum deficiency will not recover or turn green, pay attention to other growth for signs of recovery.