To PE you have answered the questions that were asked of me, which is good as I wouldn't have been able to answer a technical question as well as you have. I will also check out my regenerating of the bleach system and maybe upgrade it a bit.

I do have a query though on pre-wetting film and paper. For some years I was regularly pre-wetting both films and colour paper (EP2) then one summer I started getting Cyan streaks on the prints.

As I was at the time using Agfa chemicals I contacted them and their chemist immediately asked me if I was using a pre-wash for my prints, which I replied that I was. His next statement made me re-think about pre-wetting.

Basically he advised that we were in late summer, the dams were quite low and as a result of that, the water authorities added a flocculant to the water to make the precipitates drop. This gave them an easier chance to engineer clearer drinking water. However this flocculant also had a side effect on unprocessed colour paper.

The advice was to resist a pre-wet in both paper and film developing as it isn't required if the system is up to temperature. I stopped pre-wetting then and there, and haven't looked back since. I still have a piece of a print on the darkroom wall showing this cyan streaking caused by the said flocculant.

Since then I have gone over to roller transport paper processing and it doesn't worry me about paper, but I certainly do not pre-wet my films, either B&W of colour.