yellowing leaves

hey i have a bunch of pictures to show most of the conditions, but if you notice on 404 there is some yellow leaves happening. since its older leaves and mostly at the bottom, i'm thinking its nitrogen deficiency, but i'd like some confirmation because adding fert can go bad quick. i've only fert once 2 weeks ago with 2-8-10 or something close to that tiger bloom was the name. not all the plants are showing this, but more than 1 are having problems. if the redness is too much i can take it out, but i'm pretty sure experienced growers will be able to tell by the physical characteristics and tone compared to other leaves. i can get a white light photo if needed though.

also for more detail just put the picture name where the xxx's are and its a huge picture

www.cub3rt5x.com/pics/P1000xxx.JPG

thanks as always, and any constructive critism or props is welcomed and appreciated.

here's a video of the room if interested or concerned
www.cub3rt5x.com/ladies.avi

haven't got any responses should i take better lighting pictures?

How many hours of light per day and how big are your pots?

slk said:

How many hours of light per day and how big are your pots?

Click to expand...

we're well into 12/12 now, there is maybe 2-3 weeks left before harvest. the pots say 5 gallons, but they are more like 3.8. i guess it could be natural because i hear they drop leaves as it gets close, but it happened kind of suddenly so i'm nervous.