I couldn't help but laugh at that emoticon. xD
Yes, I think you do. The only accurate way to get the proper percentage of germall plus in your mixture is by knowing the grams of your concoction so that you know how many grams of germall plus to add. I feel like someone else can explain the process better than I can, because I haven't used a preservative yet... :P
I've heard of people measuring out teaspoons once they know what it is in grams. I dunno the ratio, though.
-2b waist-length hair (ringlets in the front and canopy, straighter under-layer)
-Dense head of med-coarse strands