Why is my Vanilla Kush dying?

[Orion64]

Hello 420 members.

My Vanilla Kush was growing really well up to two days ago. I have given a bit more feeding than usual a couple days ago. I assume its nute burn, but this normally starts from the tips right? This leaf necrosis started with these spots all over the leaves. Then moved to the tips and now looking like this. I have flushed with about 10 liters of water this morning.

Any advise? It seems that the leaves are dying fast. All this happened in about 36 hours. Here are some images:

Vanilla Kush Leaves Dying - 420 Magazine Photo Gallery

Vanilla Kush Leaves Dying - 420 Magazine Photo Gallery

Vanilla Kush Leaves Dying - 420 Magazine Photo Gallery

Grow info:
400 watt MH bulbs turned down to 300 Watt. About 30cm from top leaves.
General Hydroponics series (last feeding 4 days ago at 2ml_3ml_1ml for Micro_Grow_Bloom)
Coco/Perlite 90/10
pH at 5.8
Added some amino mix and H2O2 with Silicon plus in small amounts.

 

[4fingerlidday]

I like to dosage my nutrients using a TDS meter to get PPM reading that way you have much better control over ferts your applying and use RO water or distilled water only, now is a good time to adjust the amount of ferts I use 25% dosage at every watering and even then I may give no ferts in the 1st and 2nd gallons and the last gallon apply at 25% strength ,I learned to pay close attention to the leaves and their color and let that determine the nutrient level I apply ,cause that salt build up is real, more ferts is not better,in most cases less is better and just adjust it as needed...hope this helps