You don't get nutrient burn when they're that young? Seems a little strong to me. I'm usually sitting at about 600ppm at that stage, and my leaves look a little funky if I get any higher. What nutrients are you using?
Edit: Nevermind, just read one of your previous posts, that's what I'm using too. You must keep you ph pretty dialed in.
yes i use pH down and i dont get burns unless i go up to ~1500 then again this is my 3rd try at it haha