Minilab machines use squeeges or whatever to wipe the film down between steps. That's supposedly good enough to stop development. In a small tank at home you can't do that. So using a stop is a good idea.
Originally Posted by srs5694
I wouldn't use indicator stop. I've no idea how it would react with the film dyes.
Stabilzer stabilzes the dyes in the film. The US workers protection agency pushed the film companies over people handling formaldye. I think they wanted the workers actually trained how to be safe. Kodak reformulated thier chemicals so the chemicals make formalhdye during the processing. That means the lab workers don't have to hande a bottle with formaldhye in it. But the process still has it.