Retin-A and dry skin. Can I safely assume that my tight, dry skin means there is no more water remaining?

I have started using retin-a .025% and I've read and been told to use it on dry skin. Problem is I can't leave my skin for 10 minutes after washing as it is tight and uncomfortable (before I've even applied retinol), so I've waited for as long as possible before my skin starts to feel uncomfortable. Is that enough? Can I safely assume that my tight, dry skin feeling means there is no more water remaining?