I use TF-4 which, I understand is slightly basic. The struggle is -- do I get rid of the stop bath per the TF-4 instructions or do I keep the stop bath - per the paper instructions. I have opted to keep the stop bath but I only use it for a few seconds and add a water rinse before putting in the fixer. This keeps my fixer PH closer to where it should remain. I have ever had any problems either way with any kind of staining. I am just concerned about getting developer in the fixer. - Frank