First timer looking for input, crtitisism and help + pics

OKay so this is my first plant. It was given to me by a friend at about the first week of flowering and its been about two weeks sense then. It seems to be going down hill;I need of help. Is it a PH problem, nutes or stress? how long till harvest? i appreciate the help. thanks peace

Thats amazing if it's only been flowering for 3 weeks. Im gonna say the 3rd week after buds where visible.

Any way not bad. At this point you might just use plain water the rest of the way out for flushing PH 6.6 to 5.

Are you applying nutes or bloom?

thanks for the help freezy. yes its receiving nutes from a soil/nute mixture, although i have added some supplemental stuff into the water. do you think the yellowing and deterioration around the larger leaves is nute burn? also, i wanna say its a sativa. what do you think?