At this point - day 19 - you should do NOTHING except keep the temperature consistent at 99.5-deg-F. If you've been adding "lots of water" then the humidity has to be higher than you think (unless you're in a
very very dry climate). I suggest you don't add any more water. Too much humidity and the chick could drown in its own fluid during hatch. A dry hatch at this point is FINE. Chicks may pip and show movement for 2-3 days before hatch. Please resist the temptation to "help" it. Intervene only if you see an external pip and no progress beyond that for 24 hours.
Here is an article that will help, if it becomes necessary to help:
https://www.backyardchickens.com/articles/guide-to-assisted-hatching-for-all-poultry.72886/