I don't know about the speed of ammonium citrate but there is very little if any difference in printing speed between sodium citrate (which I believe is a lot less expensive than ammonium citrate) and potassium oxalate and if you use them both at room temperature the tone and warmth is about the same. If you use the developers at 100º F. potassium oxalate will give more warmth (more brownish look) than sodium citrate but I prefer more neutral tones and tend to use citrate more than oxalate.
Originally Posted by DrPhil
As for clearning agent I have found citric acid to be more effective than EDTA, and at $1.65 per pound in pails of 30 lbs from the Chemistry Store it is very inexpensive. Hard to believe that the Kodak Hypo Clearing Agent could be less expensive than that. You can also get sodium citrate at the Chemistry Store.
I prefer the Na2 methoid of contrast control over the A-B-C method. Both will give good results with negatives of normal contrast for pt./pd. but the Na2 method gives more flexibility for contrast control.
As for papers one of the very best is Cot-320 by Bergger. I use it right out of the package and get excellent Dmax and very good sharpness.