Magnesium deficiency? PH problem? Other? How should I go about fixing this? Overall the plant looks healthy but the lower/older leaves are starting to get some spots.. I want to figure this out before it spreads..
I am gonna go with your soil ph is likely riding the line. Test what ph is of run off to see what substrate is at. Then if need to adjust add proper ph solution till desired run off ph. Lock out from ph can cause all kinda issues. Good luck and happy growing 🌲🌲🌲👊