Hello, I bought a bottle of Pyrogallic Acid from Bryant Labs over a year ago and am getting close to an empty bottle. I recently purchased a new supply from Mike at Artcraft Chemicals. The Grade of the old bottle is "Crystal, Technical" and the grade of the new stuff from Artcraft is "Analytical Reagent 99.8% min. purity, powder". I didn't start using ABC pyro until this summer and when I did I was surprised to find that when I mixed my chemicals as others do my film had enough density to view the Sun with the Hubble. I had to dilute my chemistry to about 1:1:1:20 rather than the more common 1:1:1:7. Can the different Grades be enough to cause this difference in dilution? As far as I can tell everything else is similar to the way others use these chemicals except maybe that I use constant aggitation(I don't remember right now if that is different or not).