I think it could be a bit bigger but I'm running into the same issue. I just had to flush last night to get my ppm down. I was at over 2000ppm and I'm on week 5 with my auto flower. I did notice though when I kept it super simple with my last plant it seemed to grow great. Then I tried to hard and I stunted my plants it seems. When in doubt flush it out and start fresh. Week 4 would be good for a flush anyways, I used sledgehammer. After a flush just wait and see what happens then give it some nutes. Some say last gallon of flush give it nutes but I think waiting a few days would help your situation just because you might have some build up of salts in your medium.