Bad case nute burn

Hi there, Don’t worry much about your run off ppm in soil.I only use 50~100 and my run off always above 1500ppm until harvest.But I only use organic soil.So I don’t need to flush.For you, you are using synthetic fertilizer and needs to flush.Your plant is already in the 5th weeks of flower and I would say it’s best time to use something like overdrive for one or two weeks before flush and boost your plant.The buds will be fatten until near the end of flowering.After one or two weeks, you can check your trichomes colour and flush if you think they are almost ready.Then harvest Happy growing... ✌️