Hi THCfarmers . I have this slight tip burn all along the edge of some of my plants . I had the same thing on my last grow and I couldn’t figure out what it was . Both times it seems to have happened after I put the lights power up to 85-90% at 13-15 inches away ( mars hydro fce4800 , 480 watts ) . These are 4 weeks into flower . I will try and find the other thread where I had the same problem .
Any idea what this could be guys ?