nitrogen deficient..?

my problem is the leaves are turning yellow and dying off from the bottom of the plant just working its way up...
i read it is a N deficiency..
i got the plant about 3 weeks ago and the owner said it was about a month and a half..
it never got nutes and had sun as light befor i got it..
now im using X nutrients and im wondering if i need to add more so the leaves stop dying off!!??

Looks more like overwatering to me.

Don't water til the pot gets light as a feather...and don't try to feed it too much either...that won't help. At all...

thanks i really didnt think i needed to water this one every week, it holds water pretty good.. also idk if it is ok but i put some hydroton in the soil to hold moisture

most noobs have this problem have to let your medium dry out completely or your going to have problems