My soil may drain better but I like to use FF Happy Frog soil supplement in 50/50 with the existing soil. For bigger holes I usually add some FFOF and time release fertilizer, sulphur, calcium, bat guano, seaweed pellets and such. I add nutes on an irregular basis but as long as I mix the nutes and add them individually to each plant from a jug I don't see any burn. If I add the nutes to the water tank the plants at the end of the watering line die.