Week 4 of flowering problem

They got hot or if you are using uv they got to much UV radiation

 

When the leafs are folded like a envelope and the tips are curled up they got hot

 

Normally I keep my LED Lights 16 inches to 24 inches away .
Getting your plants hot can be as simple as hot spring days happening during spring time and not having the swamp cooler hooked up yet.
Your plant will recover, just don't let it get to hot anymore ....
Green houses get to hot without using a AC unit or a swamp cooler during the summer time .
Anything over 75 degrees F is to hot .

 

No I wouldn't stress the plant anymore at this time , wait a week or so .
Really the plant can shed its own leafs, keep the plant clean by blowing the leafs out of the plant or pick them out by hand.
I have a 8 inch 750 cfm inline fan I use to blow the leafs out with.
I would just make sure your plants don't get shocked by server temp changes or get over heated .
What you are dealing with is mother nature and don't know when your plants will get too hot or cold.

Normally green houses work the best in the winter time because they get too hot in the summer time to the point they need major ventilation and its would be easier to remove the plant out side of the green house.

 

Nobody wants to answer the question now, how can it be "too hot" if it's also on the bottom leaves?

 

There is a difference between light burn and heat stress. When a plant grows to close to a light, just the part of the plant closest to the light will show damage= light burn. When the temperature in a grow room gets too hot, the plants inside will get heat stress. The entire plant is in an environment that is too hot, so damage will be noticeable all over. In general, marijuana plants are happiest when the grow room is 75°F with 50% humidity when the lights are on and about 10° colder with the lights off. If your room is getting over 80° you will need to keep CO2 over 1000ppm or you will run into problems.

 

Make sure you add the calmag first, before anything else.