Nutrient burn?

Wondering if anyone knows what's causing the yellowing of the leaves here? Plants about 2 weeks. Thought it could be nutrient burn but then again it seems any discolouring can have a thousand reasons ..

soil is shit add 30% perlite at potup

maybe even replace that soil

either way a flush ain't gonna do squat in that mix

good luck

your over watering, some of the leaves are clawing