One plant great other maybe not so great (pictures)

Hello I’ve been growing two plants outdoors. Both are northern lights, feed around 750 ppm more so now with bloom. Ph around 6.4 in dark matter soil. The problem is one plant looks great the other very lanky and tall. I’m sure I’m missing something and would appreciate help on it.
Thanks.

gonna be a nice run looks fine just a heavy sativa is what im thinking

Looks like I had a big salt build up.... 1700 ppm on the run off water