There was an unreachable flavour that I couldn't seem to get in my Pales that others (JQ, Chris Craig, Dean) were achieving almost effortlessly, to different degrees. After dicking around with a bunch of other parameters (grains, mash thickness, temperature, hopping rates & schedules) I couldn't seem to get the elusive flavour. Did a little reading re: pale ales, and found that Gypsum and Epsom salts are essential to the profile - the common link between JQ, CC, and Dean was that they all ran well water, so I figured it had to be a mineral issue.
I'm not 100% on the science behind the addition, but yeah - the gypsum lowers pH and adds sulphates, and the Epsom adds additional sulfates (sulphates being to hops as salt is to many foods - a flavour enhancer). Scientific reasoning aside - with Fredericton water, a healthy dose of both appears to help a great deal with my pales.