Basically what is the major difference between using Sodium thiocyanate vs potassium thiocyanate in GP_1 gold protective solution? As some of you know i have been trying to find a replace for Fotospeed commerical gold toner. I thought i would try this formula. I have been using GP-1 as split toner with selenium, i.e. Jonathan Bailey's formula. I talked with the Photoformulary and they suggested GP-1 over the 231 toner. In Steve Ancells"s book the Darkroom Cookbook his formula indicates using sodium thiocyanate or one can use an equal amount of potassium thiocyanate. One is twice the cost of the other. So if money is the issue it is clear; however , is there a big difference in the results? I have the gold and i have some sodium thiocyanate already on hand, which i will try. Just curious if the results may be better if i order the potassium thiocyanate.