Looks like you could feed 600ish ppm with good runoff. They do look hungry. If I had to guess it's a nutrient build up but imbalance is the issue not salinity which is uncommon... Feeding a bit to light and you can see it's building up by the input outout numbers. Without good runoff you end up with usually salinity issues first but since your feed was so low you are seeing imbalances first. Should be very quick and easy to fix.
Up feed and increase runoff. Then make sure it get a decent dry cycle between waterings.
When you water, water to get that 10-20% run off.... Then let the plant dry out. I can't say how long as this changes throughout the grow and from grow to grow. Wait for the pots to be light almost scary light then water again using enough nutrient solution to again get that runoff
Hello guys! A quick question. Day 72, sugar leaves start truning yellow - is that a big problem and I should harvest asap or let the girl flower for 1 more week?
Still a lot of white pistols, did you check the Tricomes with a scope? I think it could go more than another week, but I am fairly new to the indoor side of things so you shouldn't listen to me.