temp is 90F !

plants are 7. week off lowering and temp is around 90F while lights on and 85 F at nights .
will my final yield be affected ?

They will be fine. 85 to 90 is common when useing big lights. It grows just fine with that temp.

You should supplement with some CO2. Would be very good in those kind of temps...

Mine were fine at that temp.

Yes your final yield will be affected. You will still have a nice harvest I am sure but you will not get as much as you would if you had the temps under control that is a fact. Get the temps under control for your next grow and you will see for yourself. Good luck dude

thanks .i cant add co2 because it is not a sealed system.
i will harvest in 2 ( or 3 ) weeks .