Durban Poison (Green Smoke Room Fast)

Lowered the main grow light to 50cm and upped the nutrients. The runt is still struggling and its third set of leaves have only begun to emerge, while the others are starting to produce their fourth. I am concerned about the front right plant, which may be showing signs of leaf septoria, a fungal disease which is endemic to the region. I will buy some copper fungicide tomorrow and apply it immediately; the infection is very resilient and sporulates readily. It will stick with the plants for the entirety of the grow if it can't be brought under control early. I am considering inoculating the leaves with a bacterial fungicide to prevent resurgence. Last thing I need is a pandemic within the tent, as well as without.