Can I use aerated water to reduce the time it takes to ferment my craft beer?

For a few months, I've been brewing with tap water as the base of my beer wort. I've had mixed results with beer taste and quality, but it's taken over three weeks to ferment. Something is wrong with my brew water, I believe. My friend suggested I try the Mayu swirl to improve my water quality, but could it also shorten the fermentation time?