Waterpik Aquarius WP-660

Waterpik Aquarius WP-660

By Waterpik · Water Flossers · Health & Lifestyle

  • Countertop unit, the only one in the comparison
  • 4.6 average rating, the highest in the comparison

Lowest price seen
$41.25
from $41.25 at eBay · Checked Oct 12, 2026

Prices are snapshots. Check the current price with the store.

Problems, parts and running costs

Summary

A full-size countertop water flosser with a 22 oz reservoir, ten pressure settings, a timer with a 30-second pacer and seven tips, ADA accepted and backed by a three-year warranty. It needs counter space, an outlet and monthly descaling — and check the box contents on arrival, because the included tip mix appears to have changed over the years.

Strengths

  • Ten pressure settings let you start gentle and work up, which matters for sensitive or new gums.
  • The 22 oz tank runs 90+ seconds, enough for most people to finish a routine without a refill.
  • The timer and 30-second pacer structure the cleaning better than bare-bones flossers.
  • Seven tips out of the box cover braces, implants and general cleaning.
  • Waterpik sells the reservoir and the handle/hose separately, so a dropped or cracked part is not the end of the machine.
  • Owners report multi-year service; several describe roughly four years of use.

Weaknesses

  • The pump is loud, the body is bulky, and the hose and cord tether it to one outlet.
  • It is a 120 V North American unit; running it on the wrong voltage voids the warranty.
  • Monthly descaling plus tip replacement every three to six months are real chores.
  • Beginners splash: expect a learning curve at the sink.
  • Hose cracking and leaking recur in countertop-Waterpik discussions, though that is a family-level signal rather than a measured WP-660 failure rate.
  • Opening or servicing the base yourself can void the warranty.

Verified specifications

Countertop, corded; the US WP-660 runs on 120 VAC / 60 Hz only.
Reservoir22 oz / 651 mL, covered and removable, rated for 90+ seconds per fill.
Stated flow13 oz/min / 384 mL/min.
1,400 pulses per minute; ten pressure settings.
Two modesfloss and Hydro-Pulse massage.
1-minute timer with a 30-second pacer; 360-degree rotating tip and a water on/off slider on the handle.
Seven tips includedfour Classic Jet, one Orthodontic, one Plaque Seeker and one Pik Pocket. Older boxes listed a Toothbrush tip instead of the fourth Classic.
ADA accepted; 3-year limited warranty.
Size10.35 in high with tip, 4.70 in base width, 3.80 in deep; 1.46 lb; 52-in cord.
Waterpik recommends monthly cleaning — a 1:2 vinegar-to-water flush followed by clean water — and tip replacement every three to six months.
Full research notes and sources

Pressure, capacity and the routine

The Aquarius earns its keep through control rather than power alone. Ten settings span a gentle rinse to a firm clean, the pacer tells you when to switch quadrants, and the massage mode pulses for gum care. The large tank is the other half of the deal: 90+ seconds covers a full routine for most users. Around braces, crowns and implants, owners repeatedly report easier cleaning.

Noise, space and cleanup

This is a small appliance with a pump in it, and it sounds like one: noise is the most consistent usability complaint, alongside the counter footprint and hose management. Plan a spot near the sink with an outlet. Cleanup matters more than with a cordless unit — wipe it down and run the vinegar flush monthly, because wetted areas that stay damp can grow mineral or mold buildup.

Repairs and upkeep

Tips wear out and should be replaced every three to six months. Beyond consumables, the serviceability story is unusually good for this class: Waterpik sells the exact reservoir for $14.99 and the complete handle/hose for $19.99, and the three-year limited warranty covers eligible US purchases. DIY repair past that is unsupported — opening the base risks the warranty — and hose trouble appears often enough in long-term countertop-Waterpik discussions to treat the hose as the part to watch, though no exact-model failure rate exists.

Is it worth it?

Waterpik listed the exact WP-660 at an MSRP of $99.99 on 2026-09-28, and Scott’s Dental listed it at $79.95 the same day; Woot sold the exact unit at $34.99–39.99 with a 90-day Woot warranty. At $55–65 it is hard to beat for a stationary bathroom routine; $66–75 remains good; $76–85 is fair; above $85 wait for a sale or compare Waterpik’s own current countertop line. Replacement parts are officially sold and modest, so the long-term cost of ownership is mostly tips. Check the store panel above for current prices.

Which model this is

This page covers the Waterpik Aquarius WP-660 in white; the Amazon listing is ASIN B00HFQQ0VU. The WP-662/663/667 are color variants and the WP-670 is the Aquarius Professional, a different model. The US unit is not dual-voltage and should not be run overseas on a plug adapter.

Sources

Manufacturer:

Independent reviews:

Owner reports:

Listings:

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