Nitrogen deficiency or plant shedding old leafs?

[GenieMan]

My autoflowers about 9 weeks old and the bottom leafs are turning yellow and seems to be climbing up? I just gave it half dose of DR Earth Bloom 2 days ago so not sure if its a nitrogen problem? Plants also like 6 feet tall...ya half my fault cause I had my light 2 feet away for most of the grow which it said in the book to do....wrong. Thanks for any input.

 

[GenieMan]

Strain: Northern Light Auto
# of Plants: 1
Growth Stage:Flowering 9 weeks
Grow Area Size: 3x3
Air Temperature: 73
Relative Humidity: 65
Ventilation: Fan
Lights: King Plus 600 Watt (125 actual)
Grow Type: Soil
Medium: FoxFarm Ocean Forest
Pot / Bag / Bucket & Resevoir Size: 3.6 Gallon
Nutrients: Dr Earth Bud Bloom 1/2 dose once every week
Solution Temperature: N/A
Solution PPM: N/A
Solution pH: N/A
Pests: Fungus gnats but under control with sticky traps

 

[GenieMan]

The leafs turning yellow are on the bottom fan leafs...not sure if I should add more bloom nutes or a dose of all purpose dr earth fert?

 

[GenieMan]

More images

 

[GenieMan]

Anyone? More nutes? Looks like its working itself up.

 

[growsince79]

I'd feed it again at least one more time.

 

[GenieMan]

Alright so another round of nutes. Thanks for the help.