What is your replenishment system?
At my stated rate, which is 50ml of fresh solution of potassium oxalate for every 80-100 square inches of prints developed there is a 100% turn-over of all of the solution in a liter of developer for every 6-7 prints of 12X20 size. At this rate of replenishment I have not had any problem at all with consistency.
With kallitype, where I use sodium citrate, I must replenish at a much higher rate to avoid staining from ferrous build-up. In fact, my prefered way of working with kallitype is to just use the developer one-shot and then discard.
Originally Posted by Michael Mutmansky