I have just had a surprising experience (I wish I did not have it) processing film with the Dixactol homebrew formula. It has been working well and giving me excellent results. Until yesterday! I am using HP5+ @400 asa. Suddenly a film I processed, exactly the same way as previous ones, does not have any stain! The negative is well developed but definitely does not have any stain. I have compared it with other negatives of the same film type and scene.
Out of curiosity, and frustration, I made up a fresh batch of Dixactol type homebrew. I put a film through it and it worked perfectly! What I cannot understand is that during the processing sequence this developer appears to behave the way it should, e.g. when I add part 'B' (sodium hydroxide) to part 'A' it immediately changes colour. When I dump it after development it has changed to a very dark 'tea' colour (which it should).
I only use a water stop bath and an alkaline fix. What is confusing is that the negatives are developing. I would have thought that any contamination of either stock solution would result in no or very little development! I wonder if this developer has 'died', but I only made it about two weeks ago. It is stored in minimal air space dark glass bottles containing marbles. Has anyone any possible suggestions as to the cause of this problem.