Waterpik Ultra Water Flosser vs Waterpik Aquarius WP-660

Both are corded countertop Waterpik flossers with 10 pressure settings and a 90-second reservoir, so the cleaning job is similar. The Aquarius WP-660 is the better pick for most people: it adds Floss and Hydro-Pulse Massage modes, a 1-minute timer with a 30-second pacer, and ships with 7 tips, plus a 3-year warranty. The Ultra WP-100 is simpler and a long-standing favorite with a large owner base, but it has fewer tips in the box and no timer or massage mode.

• Choose the Ultra WP-100 if you want a straightforward, proven water flosser with 10 pressure settings and a 360° rotating tip and don't need a timer or massage mode.
• Choose the Aquarius WP-660 if you want the extra modes, the 1-minute timer with 30-second pacer, and the larger tip kit, especially for braces, implants or gum care.