Hello It's almost harvest time for my grow! My leaves turned yellow after my last flush at 500ppm can you help me? I need advice!
Take a picture without the led light on. This is normal. Especially since you're doing a flush. How many weeks to you have left like 2-4?
Normally I would say this is normal end of harvest , flushing same ol same ol . But the lower leaves are vibrant and green while the top leaves are discolored and lack vigor . Which leads me to believe a different problem.