I’m growing 3 GSC autos that are about 5 weeks from seed. I’m growing in Fox Farms Ocean Forest. I understand it’s a hot soil, only watered for 3 weeks. On week 4, I started LST and fed advanced nutrients grow/bloom/micro at the lowest recommended dose of 1ml per L. Within a couple of days I noticed the leaf tips brown, so I returned to water only thinking it was nutrient burn. Now I’m starting to see additional brown spots. Is this nutrient burn or something else I need to be concerned about?