Northern lights auto

After doing some research, I didnt think flushing was needed, b/c of living soil. I started checking my ppm it was sky high like 20k Thought maybe doing to gallons of water and checking ppm. it was still super high. Scared to put more water in her b/c of last time I gave her a bunch she wilted. been so paranoid of Fking this up. so 2 gallons 6.4ph. Also I havent been sure if me doing the air stone and not being able to check the Ph. for some reason I still watered it and I should have tossed it and waited. live and learn. 1 more water in this week I did 1 gallon 6.4ph and checked the run off 6.5