why is she turning yellow?

[punkster415]

she started turning yellow about 3 weeks into flower when i put her under the 1000 watt what could be the problem i am feeding it just water right now

 

[bombbudpuffa]

She needs NITROGEN...BAD!!!

 

[Growdude]

She needs NITROGEN...BAD!!!

Yep plant looks hungrey, while it is common for plants leaves to yellow in the late stages of flowering, I think yours are N deff.
At this stage I would give them nutes but dont over do it.