day 4 of yellow scare

[smallstar]

I've been fighting a yellowing on my tall plant in the flower room. I've had some people tell me magnesium and calcium lockout, nitrogen deficiency. Iron deficiency, and heat burn! Yay!
Now all this started after adding some budding nutes to my DWC tank. It was also thought that I messed up the ph at this point locking out stuff.
I've taken these steps:
Flushed the system with ph 5.6 water, and I've added half strength nutes today. I'm hoping to see some changes soon. The one thing however that doesn't make sense is that the shorter plant in the flower room doesn't have this problem "yet". But both plants share the same water. This is what leads me to the too much heat at the top of the flower room.

Any thoughts and comments please! I would love to know I'm on the right or wrong track.

 

[smallstar]

Today, FINALLY! I'm seeing green return, even under the LEDs. I have to say, the change took place when I re worked the whole air flow and venting in the flowering chamber. This is not to say it isn't the changed out 1/2 strength nutes, but the heat that the combined CFL's, LED's and normal FL's were making the top of the chamber too hot and humid. This would also explain why the shorter plant didn't have the same problem even though both are drinking the same hydro water solution. Still too early to pin my ride on one horse, but i'm wondering if these new high powered LED lights can get to be too much, too close with or without the heat.