Chapeau for your work, David! This has to be said!
Anyway,sometimes I have the impression that “this replenisher and starter” issue is somehow misunderstood and easily mixed up with other inconsistencies that like to happen in hobbyist cellars, at least in mine…
In commercial processing, a fresh working solution is only made once, if the machine is filled the first time (in general). From the moment a film is/was processed only a small amount of replenisher is added to the tank solution to maintain/control its chemical activity. Depending on the subsystem it can be something like 70ml, 45ml or 22ml for each Film 135-24. Because of pH drop during development and accumulation of restrainers as well consumption of developer and preservatives this replenishing solution is slightly different. The ph is more alkaline, sulfite, hydroxylamine sulfate and CD4 are about 15-20% increased, bromide level is only about 1/3 to half, iodide is absent at all, etc. The absolute values are depending on the subsystem (Brand, High rate, low rep. rate etc)
So the replenisher has different composition, is quite hot and needs the addition of the starter to be converted in proper tank solution. From then on only replenisher is needed in commercial processing. Tank solution is that what hobbyists need / label as developer.
Bottom line: If using a commercial developer replenisher that requires starter to get transformed in to seasoned tank solution, it will be better to use it in the right proportion, if the primary target is a negative in specs in a non replenished development cycle (Assuming agitation, times and temperatures are in specs too). For experimental / fun everything else can be done… I’m frugal my own way by home brewing that stuff…
Last edited by stefan4u; 01-14-2013 at 07:33 PM. Click to view previous post history.