Restarting Celery - 4 weeks

I checked the restarted celery today to see if there's much change.  It still look well, however, the new growth appears to have tailed off other than getting a tiny bit taller.

Here's a comparison of a picture today (left) and the one from my last post (right).

I need to go re-pot a peace lilly today, anyway, so perhaps I'll see how transplanting in soil helps.