Yellow tips on all leaves 2wk until harvest

Hey so I've noticed on all of my plants leaves that the tips are yellow on every one I had a read through the stickies to see if I could solve the problem but I'm not 100% sure what is wrong. I've uploaded a pic, if anyone can tell what's wrong. Running a bubbler hydroponic system using canna Nutes 2weeks until harvest

No worry in fact that is normal to an extent. This happens because of lack of nutrients due to flushing

I don't think I'd worry about it with two weeks to go. Leaves look very healthy.

Happy leaves. i see that all the time Except in organic grows