Hi comrade. May show signs of calcium deficiency if the pH in the roots is too high or too low. This is because when the pH of your root zone is off, your cannabis is unable to properly absorb calcium through its roots. Therefore, the first step is to ensure that your medium has the right pH. i guess you need to reduce your ph 6.0 / 6.2 water a couple with this water and if it doesn’t improve again start using nutrients again. mark the correct answer later I am curious. good luck .