Problem With a Red Dragon

Hi,
i have one Red Dragon ( Barney's Farm) with some problems...
She is under a 600w with cooltube in a 12 gallons dwc bubbler system.
I fed her with lucas formula then i switched to ghe formula (3/2/1) and yesterday i change the reservoir with Ripen(4 ml per liter).
I would like to know what it could be happen in the last two weeks...
Do you have any ideas?

Probably it is nute burn...
but the ec was only 1.8 ([email protected])

this is natrual. the leaves sometimes dry and fall off in the final weeks of flower. The buds are draining the nutrients from the leaves.

So with more nutrient she would be ok? She will stop to eat the nutrients form the upper leaves and start to take it from the roots?

p.s.
It could be Nitrogen toxicity? Marijuana Plant Abuse says:

Nitrogen Toxicity:
Leaves are often dark green and in the early stages abundant with foliage. If excess is severe, leaves will dry and begin to fall off. Root system will remain under developed or deteriorate after time. Fruit and flower set will be inhibited or deformed.
With breakdown of vascular tissue restricting water uptake. Stress resistance is drastically diminished.

it could be a little bit of nitrogen deficiency but I still think it's normal and won't harm the final product. give her about 1 more week and cut her down