Tracked by Evreward since 2009, Aquasana offers coupons, cash back rebates and rewards, with savings as high as 55% off. Aquasana discount coupons are seasonal, appearing every three to four months, and are often more valuable than similar merchants. Even when Aquasana doesn't have a coupon, you can always get up to 20% cash back, and other great rewards, with every purchase.