I noticed a few yellow spots onMonday and thought it was leaf Septoria. The yellow spots do not rub off but are spreading.
I am using fox farm HF and just started using CalMag on Monday at 4ml/gal. The water is RO with and adjusted pH of 6.5. I can’t think of anything else. Except I started to CalMag too late.
Strain; Type, Bag
Soil in pots, Hydroponic, or Coco?
PH of runoff or solution in reservoir?
What is strength of nutrient mix? EC, or TDS
Indoor or Outdoor
Light system, size?
Temps; Day, Night
Humidity; Day, Night
Ventilation system; Yes, No, Size
AC, Humidifier, De-humidifier,
Co2; Yes, No
If you can, upload a picture of your plant. It helps the diagnosis, if needed.