nitrogen? again? pics

hey guys so i had been giving my plants cal mag for a couple weeks and then they started to show signs of something bad, so i dropped the cal mag and went to straight water. after a couple days this yellowing and browning and curling started to happen. do i just need to use cal mag again or is this something differant?

looks like it needs nitrogen.

they look fine to me, a bit out of whack because of what youve done but otherwise ok,go back to your feed schedule and try not to let every little dodgy leaf make you panic into killing them by trying to help.