I've been pre-soaking for years in tap water. It makes sense to me to expand the emulsion then drain for a couple of minutes to remove excess moisture. This allows for a more immediate and complete saturation response from the film to the chemestry in the initial moments of processing. Once I started this streaks and bubbles dissapeared in my process. I'm still a dip and dunk guy in 3 1/2 gallon tanks so it could be an inherant need.