Top 44 Problem

[Green Love]

This is my Top 44, i just got my first set of white hairs at all my bud sites about a week ago. My problem is that the bottom leaves are turning yellow, fading out from green to yellow. Ferts are right, all is right, maybe expect I just add extra ferts 2days a go, but before that the leaves had already started turning yellow. Heres 2 pics, any ideas?:

PICT0145.jpg - Image - Photobucket - Video and Image Hosting

(http://s533.photobucket.com/albums/ee340/rumantea/?action=view&current=PICT0145.jpg)PICT0143.jpg - Image - Photobucket - Video and Image Hosting (http://s533.photobucket.com/albums/ee340/rumantea/?action=view&current=PICT0143.jpg)