35% Hydrochloric Acid on the label. For the Head treatment, do you mix this 8 parts of water and 1+ part of Muriatic Acid for a 12% solution.

Or, since the stuff in the bottle is already 35% Hydrochloric Acid, do you mix 2 parts water and 1 part of the Muriatic Acid, to get to 12% Hydrochloric Acid ?

thanks, cheers, John