My local shop was out of Kodak Rapid Fixer yesterday so I picked up a bottle of Ilford Rapid Fixer. When I got it home, I realized that is does not include hardener. It's active ingredient is even something other than traditional hypo. If I use this with film, do I risk that my negatives will be easily scratched? I know there are non-hardening fixers but I've been used Kodak Rapid Fixer for so long I don't recall ever using a non-hardening fixer.