Patrick;

I am all for both methodologies but one must be differentiated from the other. One is professional and one is by necessity and that must be clear to the user and he/she must know the reasions behind both.

Several years ago I did try to show you the volumetric vs gravimetric measurements and the errors involved and you disagreed with me then just as you seem to now. I gave an exact figure on Photo Net in my post about 2 years ago and here we are again at the same point.

As for flashpoint, I had to explain it to you. You were advocating a potentially dangerous method of mixing chemistry that could cause a flash fire. You see what lack of experience or knowledge can cause? It can lead to a fire in someone's home and I was trying to HELP you avoid a potential law suit.

So, what is in the Potassium data? The chart is totally in error in all versions of Mees. That is apparently why Howard left it out of Mees and James. It reports no data for Potassium and suggests that Ammonium hypo is slower to fix than Sodium hypo, a gross error. So, the figures were corrected in Haist.

It seems that the Cation of Hypo is critical in fixing and therefore must be a criterion in the purity of any generally used photochemical. We did not confirm that until just before Haist published, but after the last version of Mees. So, there must be a maximum allowed level of Potassium in the spec for Hypo itself, you see?

This, BTW, is at the root of the controversy involving TEA in fixers. I will only comment that in a TEA containing fixer, it behaves as the Cation (the ion with a positive charge) and this is where there may be problems. IDK due to uncertainties in published literature.

Design of photographic solutions requires years of work and study Patrick. I am willing to help, but not willing to see information go out with errors by omission or comission. Please see my POV for the sake of the future.

I respect the work you have done for those not able to use weight measurements, but I would like to see the differences and problems explained. The same is true of using grocery store chemiclas. It is important, or we can begin a backslide.

After all, what use is it to pay a premium for a film product from Kodak Fuji or Ilford only to process it in the equivalent of laundry detergent?

PE