Classic case of N def? Pics Included

I know when it starts to yellow that its N def but was wondering what was with the Brown crispy tip?

Thanks,

potassium. looks like you might have to up your nutes.

It would help if you gave us some info.. is it hydro or soil... what nutrients are you using and how often? maybe a picture of the entire plant..

Potassium makes more sense thanks. They are in a soiless mix, and the plant they are growing from went nutty on me and a split off in a V, if you go to my profile and go to the thread I started you can see the entire plant (thread is called: What causes this?). As for watering I water we the plant needs it, once every 5-7 days. And use a 2 part nutrient mix.