leaf brown spots yellow leaves

Plants are going through somthing . Water as needed by hand using nftg no4 soil.cutting edge solutions full line. Enclosed grow running ac temps are 80° dehumidifier keeps it at 40% under 600w hps 2 weeks into flower

I am trying to figure out if this is a potassium deficiency or light burn/heat stress. I am growing indoors, in ocean forest soil. I am 3 weeks into flowering on an auto flowering northern lights. I mainly water when the soil is dry, about 2-3 times a week. Every other watering contains fox...

Hey all, For the past few days I've been noticing my plant has been showing multiple yellowing/brown, some drying, and curling of the leaves I panicked so I trimmed the leaves assuming since they were dying off already. For the last two days I've noticed the following yellow/brown in...

HELP Wanted! Yellow leaves and brown rusty spots. See attached photos. Any ideas? I think it's a DEF. as the plants have only entered preflower and i was using half strenght biobizz. LIGHT: 250W HPS + sunlight when its available 24/7 (considering switching to 20/4?) TENT: 80x80x190 SOIL...