Help Yellow and Brown, may be going down

[Treeoftao]

Ok so I'm a total newbie, I was having some success and then BAM... this yellow/brown leafy problem has arisen, I need some suggestions stat. Take a look at the pics and tell me what you think.
http://i60.photobucket.com/albums/h26/TreeofTao/th_IMG_5860.jpg (http://i60.photobucket.com/albums/h26/TreeofTao/IMG_5860.jpg)
http://i60.photobucket.com/albums/h26/TreeofTao/th_IMG_5863.jpg (http://i60.photobucket.com/albums/h26/TreeofTao/IMG_5863.jpg)
http://i60.photobucket.com/albums/h26/TreeofTao/th_IMG_5864.jpg (http://i60.photobucket.com/albums/h26/TreeofTao/IMG_5864.jpg)

[mscaboo]

going to need more info,ph of soil,nutes,temps,size of bucket,how big is the plant?