Ryuji,(posted 8278 days ago)yes, I probably have problems with tap water. When I started photography I tried to use plain tap water. The result was hours of retouching the prints. I tried a variety approaches: I used filtered water, I used distilled water for final bath only (after rinsing), -- all this only _partially_ removed the dirt. When I switched to distilled water it solved the problem completely: my negatives are absolutely clear; I almost never need to retouch, only if I have missed a tiny dust spes while enlarging.
Yes, I know that some salts dissolved in rinse water speed up the removing the products of fixations; the 2% solution od Na2SO3 (Sodium sulfite) is a cheap and one of the most efficient means; by the way Kodak hypo clearing agent consists almost entierly of this substance (in spite of some additions intened for hard water). And I've used sometime this 2% solution bath immediately after fixing, but I could not detect any difference: I fix carefully, and 5 steps mentioned above were pretty enough.
"A bit of water carried over is not a big issue with good agitation." -- Ryuji, I'm not sure if I described my procedure clearly enough. I don't use running water (there is no running distilled water supply), I use static procedure: I fill the tank with water, wait agitating, drain, then refill. This cycle repeats 5 times. My point was the more water you carry over to the next step, the less efficient becomes the procedure, in other words 5 cycles can be not enough. If you're curious, I can email you the formulas showing that if we increase the carry over amount, the efficiency of the wash drops, and drops greatly.
Regards Andrey