looks really healthy man although 1900 ppm sounds awful high, i thing the experts would say to get it down to around 1500.

that being said, your virtical growth should all but stop now, in the 5th wk of flowering i would expect most of the new growth to be in the buds.

like you, i'm on my second grow overall and my first in hydro and like you, i love it.

if you could post some pics of your set-up that would be great.

btw, if you aren't cloning yet, you need to learn how, it's not hard really and, once you know you have a female, you can replicate her so you can have as many female plants as you want.

anyway, good luck, let us know what you yield

(come check out my imaginary garden, i built a cloner you could use)