I use drums and they are washed between each use so I dont think tar is a problem for me. I agree, the developer as tweaked seems very good, and the other formula does involve some expensive/hard to source chemicals.
I am about to use up my liter of "tweaked" developer, and will make up another batch with the original amount of carbonate and maybe 6g CD3, and see what happens. I want to end up with one formula optimized for general use, and one for printing ECN-2 negatives.
Reflectin on PE's comment that you posted above -- I wonder what would happen if one were to take out triethanolamine and replace it with benzyl alcohol?
The RA4 developer uses Hydroxyl Amine Oxalate to prevent stain and tar and to help reserve the developer. You can substitute Hydroxyl Amine Sulfate with the correct adjustment in amount. The recommended brightener is chosen to prevent yellowing with keeping. Some brighteners yellow heavily with age.
PE indicates that HAS can be used as a preservative.....is that all it does? The formula we have been discussing works pretty well, and now I'm wondering what would happen in the context of C41 developer if HAS were omitted? Because it's one of the more expensive ingredients.
I have tried C-41 developer without HAS and with pH adjustment seemed to work well, but one would expect a shorter shelf life.
What did you use for the pH adjustment? More carbonate?