Help! Leaves burning

[MickyPolau]

Good evening guys,

Since 2-3 days my leaves look are they are burning. I am almost sure its because of too strong HPS light. I am using 300 WAtt HPS, and a fan blowing on the leaves when the light is on.
I can not get the temperature under 30degrees (85 farenheit).
Last Saturday I lowered the light up on advice from someone, so maybe thats the reason why they started burning.
Today I raised the light again to prevent further burning.

Please if you have any experience with this problem give me some advice.
I would be really thankfull

info on pics:
The first three pics are from my tallest plant, and thats actually the plant which has the most burned leaves
The fourth pic is from my growbox, with the light at the hight it is now
the last two pics is an overal pic of all the plants.

 

[namvet25]

Ya, it looks like heat stress with the curled edges85 degrees is about as high as you should go.

 

[JM]

yup... heat stress...
put your hand under the light where the plant will be.... see how hot it gets after 30 seconds or a minute... thats how hot your plant will be there...

 

[MickyPolau]

This morning the leaves still looked the same, if not even worse. It also looks like some leaves start to be a bit yellow, just a bit, or maybe its because of the light, im not sure.

Any recommendations I can do?
I raised the light already, amd a fan is blowing on them when the light is on.
Cheers guys