Leaves green and brittle help!

[Cp420]

Problem: fan leaves are green and brittle like they havent been watered and the viens on the leaves are turning brown

Medium/grow method:
Soil

Feed: and supplements used:
1tsp epsom /5l water havent used ferts in a week thought my original problem was nute burn

water source:
Tap water phd to 6.5
Strain/age:
Auto feminized
Northern lights / 1.5months old

light used:
Hps light 600w 24/7
Climate:
Temp top of box 24 Celsius
Temp bottom of box 20.5
Humidity 20%
Additional info:

 

[Arthur]

There is more there than this, but, for HPS, your temps are fine... your rH sucks. Low rH causes plants to transpire more, drawing up more nutrients. Thus your "nute burn". Not over fed, it's your rH. With no flowering plants, mid veg, you should be closer to 65%.

 

[Cp420]

Ok i put a humidifier in my tent and am monitoring the increase
thanks

 

[Arthur]

if you try and follow the chart throughout, you'll see better health, and faster growth. I was actually very suprised at the difference in growth rate by just bringing my temps up. I was a long time hps guy, and when I switched to led, I struggled looking at a thermometer in the low 80s... like fingernails on a chalkboard... but, seedling growth took a drastic jump. Then I stumbled on the VPD charts and started digging.