I've been coming to the attention of 510 Pyro and it may be what I'm looking for in a developer. But, why isn't this stuff commercially available? Photographer's Formulary doesn't seem to offer it despite some other Pyro developers. From what I remember reading once mixed it lasts a real long time. Is there a commercial scource or am I stuck having to buy and mix the basic ingredients? Plus, I'm a little confused on how to make this stuff from what I've read online where it lists TEA twice as an ingredient, lastly TEA to make 100ml. I would appreciate clarification on this... Thanks.