You probably already know but I will just add that as the flower stage progresses and nears to an end, a plant is suppose to yellow up and lose its leaves etc. Also, when you get to the 2 week window when you know you will need to harvest, you must stop all nutes and water with just pH water as said by the other helpful gardeners. You will have a horrid taste in your meds if you do not! Yes I would move that constant AC flow off that plant... I dont have a clue on the output air temp it is giving, but thats what that plant is getting which is much lower then its desired range.. Of course its going to tell you... im too cold!