So, well, I'm an idiot. I had some pre-mixed fixer (Ilford Rapid-fix), it was a few weeks old and I couldn't remember how many films I'd put through it, so I tipped it out (probably for the best anyway). Now, I've just started developing (135-36 APX100 and a 12-shot hand-rolled Rollei Retro 100, 8+750ml rodinal 1-hour stand), mixed up the stop, went to mix up the fresh fixer. Oh crap, i'm out. Well, almost. Probably about 40-50ml left in the bottle. So in my Paterson 4 tank I need 700ml to just cover the two rolls. That makes it 40+640ml, a 1+16 ratio, whereas in the past I've used 1+9 for a few rolls before ditching it and making fresh. So, questions is, will it be enough? Having re-used fixer in the past, I'm hoping that there's enough active chemicals floating around to fix the bits that need fixing, and by leaving it in longer and agitating more I'll get those chemicals to where they need to be. It's 8pm and getting new fixer within 24 hours is out of the question, and developing's already started. I'm thinking if I hadn't tipped the old stuff out I probably could have at least topped it up and it (probably) would have been fine (for future reference, is it ok re-using weeks-old fixer and topping up a bit? or does it go bad?) Back in high-school, I remember leaving papers in the fixer tray until the end of the class, then we fished them all out and hung them up afterwards with the lights on, so I'm presuming there's no danger of 'over fixing', i'm more concerned about underfixing. Maybe if I just leave it overnight I should be fine? Any dangers of over-soaking the films or anything?