Looks like a nute burn/lockout of some sort.
Are you growing in dirt?
How's your silica level?
How's your potassium level?
Both of those are important for the plant to resist stress.
K deficiency can cause the blackening of the leaves.

Another thing, you have to raise the temperature by almost 10 degrees if you want to use CO2. 65 degrees with CO2 is NOT beneficial. You need to be in the 75 night/85-90 day range to use it properly.

Is this your first grow?

By the way this 'help' and 'help 2' multiple posting is annoying as fuck. If someone doesn't answer you in like an hour you don't have to post the same thing again in a new thread, just add the pics as a reply to yourself.

I'll try to answer specific questions, but you need to give more information about your whole setup, all in ONE THREAD where I can find it.