I don't know if I would chance it, we lost some eggs because of no water. We thought we had plenty of humidity here in the South but the bottom line is we should have followed the incubator instructions which was to add water! Good luck,
You'll find that different humidities work for different ones of us. We all have different conditions. If you have a local mentor to help you through the process, that is a great resource. But beware that just because something works for one does not mean it works for all. Where you incubate, you may have a different humidity due to the air conditioning, for example.
My suggestion is to try a method, try being as consistent as you can throughout the incubation process, use eggs that are not real valuable until you start to achieve success, and analyze the results so you can see what you might need to change next time.
I live in Oklahoma, Southern Oklahoma. I have a hygrometer, and I keep my hygrometer at 25 to 30 percent during the first 18 days, when I incubate chicken eggs. And the last 3 days I keep the humidity at 70%.