With all due respect, OP doesnt need any further nutes at all. My advice would be to find out an accurate representation of that soil medium. The problem is here in South Africa we cant get alot of things at the moment, grow lights, ph pens etc are all sold out. I want to invest in a blue labs soil pen, allows you to stick the probe right into the soil and test directly. Some think its a waste of money, i think it would be an epic investment to grow consistently good cannabis which in turn brings your cost down on things like electricity when your flowering or veg period is extended due to messing things up.
Anyway, i would suggest getting some PH up from hortistore, and then slowly ph the waterings up little by little until your issues are resolved
hydroponic.co.za
