Since this question has come up again, I found that when using a water "stop" bath and TF-5, I would sometimes get staining along my print edges. Going to a *weak* citric acid stop bath solved that issue (along with being very careful when handling the wet print).
I have been using full strength stop for a short period, but now I think I will fall back to a weak acetic acid mixture to try to extend the fixer life a bit more.
Maybe a pint of working stop added to bring the tank up to 2 liters? I will experiment.
If I were using trays, I would go full water (unless I got staining), but since I am using a Nova slot processor, I think the weak solution, changed every week or so depending upon print volume, might work better.