Beachwalker
Well-Known Member
You're running your lights at night, and off during day? I was reading about sorbic acid (or potassium sorbate), and thought of your plant disease, septoria. Pesticideinfo.org says potassium sorbate is classified as a fungicide, while California included it in our "can use" list. I haven't read much about it in relation to plant diseases, it's a common food preservative, there's a bit of food science available on its use.
Another approach to consider would be a phosphite of some variety.
Thanks for the input! Septoria season is long over. I fight it with baking soda, copper fungicide, neem and sulfur burning. Proper control would be an adequate dehumidifier, but I don't currently have the extra 600w electricity available.