Darkroom Tip: Water Bath or Acid Stop?

An acid stop bath halts development in seconds and protects your fixer from carried-over developer. A plain water rinse (fill, agitate, dump — twice) stops development almost as fast for film and eliminates any chance of pinholes some workers attribute to vigorous acid stops.

For film, either is fine. For prints, use a proper stop bath — dev-soaked paper carried straight to fixer exhausts it quickly and can cause staining.

The real rule: pick one method and keep it constant, because your development time silently includes however many seconds your stop method takes.