Quick Answer
The Waterpik Aquarius (WP-660) and Ultra Professional (WP-662UK/WP-660UK) are functionally identical water flossers with the same core technology and plaque removal effectiveness. The main differences lie in retail packaging, included accessories, and regional power compatibility rather than performance capabilities.
Key Points:
- Both models feature identical 10 pressure settings, 1-minute timer, and high-capacity reservoir
- Both remove up to 99.9% of plaque with the same clinically proven technology
- Differences are primarily in packaging, accessories, and power adapter compatibility for different regions
The Waterpik Aquarius (WP-660) and the Waterpik Ultra Professional (WP-662UK/WP-660UK) share the same fundamental technology: a high-capacity reservoir, 10 pressure settings, a 1-minute timer/pacer, and the clinically proven ability to remove up to 99.9% of plaque. They are functionally almost identical, differing mainly in retail packaging, accessories, and power compatibility.
Waterpik Countertop Flosser Comparison: Modern vs. Legacy
The key distinction is that the Aquarius and Ultra Professional models (the 600-series) are superior to the Ultra Plus (the 100-series) because they include vital guidance features like the timer and massage mode.
| Feature | Waterpik Aquarius (WP-660) | Waterpik Ultra Professional (WP-662UK) | Waterpik Ultra Plus (WP-150UK) |
| Model Type | US Flagship (Best All-Around Value) | UK Flagship (Locally configured) | Older/Mid-Tier (Legacy Model) |
| Regional Plug/Voltage | 120V (US/Canada only) | 230V (UK 2-Pin Shaver Plug) | 230V (UK 2-Pin Shaver Plug) |
| Massage Mode (Gum Stimulation) | Yes (Hydro-Pulse) | Yes (Hydro-Pulse) | No (Lacks this mode) |
| Timer/Pacer | Yes (1-min timer / 30-sec pacer) | Yes (1-min timer / 30-sec pacer) | No (Lacks this vital guidance) |
| LED Indicators (Function/Mode) | Yes | Yes | No |
| Water Control on Handle | On/Off Slider (Best for smooth pausing) | On/Off Slider (Best for smooth pausing) | Pause Button (Less intuitive than the slider) |
| Included Tips | 7 Tips (US Standard) | 5-7 Tips (Varies by UK retailer) | 6 Tips (Includes Toothbrush Tip) |
| Tip Storage | Handle slot for 2 tips | Handle slot for 2 tips | In-Lid Storage (Holds multiple tips securely) |
| UK Price (As listed) | N/A (Requires converter) | Often on sale for £59.99 – £89.99 | £114.00 (Currently overpriced) |
Key Takeaways for Buyers
- Best Features & Performance (The Winner): The Waterpik Ultra Professional (WP-662UK) is the superior choice for UK users because it includes the essential Timer/Pacer and Massage Mode, which the Ultra Plus lacks.
- Legacy Model Warning: The Waterpik Ultra Plus (WP-150UK), despite its higher current retail price of around £120.00, is the functionally inferior device due to the lack of the built-in timer and massage mode. Its main advantage is the dedicated tip storage case.
- Regional Restriction: The Aquarius (WP-660) is only suitable for North America (120V) and should not be purchased by UK users unless they plan to use a large, expensive voltage converter.
Key Differences Explained
The Waterpik Aquarius (WP-660) and Ultra Professional (WP-66xUK) differ primarily in voltage/plug, included accessories, and cosmetic accents.
1. Power and Regional Compatibility
The most critical difference is the power requirement:
- Aquarius (WP-660): Designed for North America (120V). It will not work safely or correctly in the UK without a robust voltage converter, as the required voltage is different, even with a simple plug adapter.
- Ultra Professional (WP-66xUK): Designed for the UK (230V) and comes with the necessary 2-pin UK bathroom plug for immediate and safe use in a UK shaver socket.2
2. Included Accessories
The specific model number can affect the included tips:
- The US Aquarius (WP-660) explicitly includes 7 tips.
- The UK-market Ultra Professional (WP-662UK)explicitly lists 5 tips, while other listings for the WP-660UK variant may list 7