well it starts with the water and then how much nutrients you're putting in affects that water. Its a good idea to know what the PH of you water is before you start adding nutrients and then add accordingly. Cannabis likes a PH between 5.7 and 6.2 so slightly acidic. What I see is your substrate is thrown out of whack. A good starting point is to flush your plant with PH'd water and to check the runoff of that. from there once your run off is at the PH you're at I would start adding in nutrients but make sure you're feeding your plant in the PH range. I would look into it a little bit as well, theres tons of info on the web.
If you don't feel like buying a PH pen and want a relaxing grow next time and don't want to worry about PH fluctuations I would check out Mantis Buffered Nutrients. It's a one part nutrient that is PH buffered so it sets your PH in optimal range throughout the plants life cycle. I use it and have been for 3 years because I don't have time to be messing around with feeding schedules and PH and all that. Makes growing easy and fun haha
