Five Cent
Waterpik Aquarius (WP-660)
The countertop water flosser with 10 pressure settings, a 22-ounce reservoir, seven tips, a three-year warranty and the ADA Seal stated on its page
Scored on the published rubric, from documentation, pricing and verified user reports.
Best for: People whose dentist has flagged between-the-teeth cleaning, especially with braces, implants or bridges, who have counter space and an outlet near the sink.
Verdict
The Waterpik Aquarius WP-660 is the best-documented product in this oral care set, and this documentation review grades it on the Waterpik product page, the WP-660 versus WP-670 compare table and the ADA's published criteria, all read on October 16, 2026. Waterpik publishes everything: a 22 oz (651 ml) reservoir with 90-plus seconds of run time, 10 pressure settings, 1,400 pulses per minute, 13 oz per minute flow, seven tips by part number, a one-minute timer with 30-second pacer, dimensions, weight, cord length and a 36-month limited warranty. It states ADA acceptance for safety and effectiveness and cites three named studies for its claims. The caveats are also clear: it is a corded 120 V countertop unit for North America only, the PSI range is not listed, and the Waterpik store showed every color sold out when checked. Owner rating on Waterpik's compare page is 4.64 out of 5 from 2,893 reviews. For interdental cleaning on a counter, this is the reference product.
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Where it is strong
- Full specification published: 22 oz reservoir, 90-plus seconds, 10 settings, 1,400 pulses per minute, dimensions, weight, cord length
- Seven tips in the box by part number: 4 Precision, 1 Orthodontic, 1 Pik Pocket, 1 Plaque Seeker
- Three-year (36-month) limited warranty, the longest in this set
- ADA acceptance for safety and effectiveness stated on the product page, with the Seal's wording about plaque and gingivitis
- Owner rating 4.64 out of 5 from 2,893 reviews on Waterpik's compare page (October 16, 2026)
- Claims cite named studies (Barnes 2005, Sharma 2008, Tufts 2014) rather than bare percentages
Where it falls short
- Corded countertop unit at 10.35 in tall and 1.46 lb; needs an outlet and counter space by the sink
- 120 V / 60 Hz, North America only; not for international travel without a converter
- PSI range for the 10 settings is not listed on the product page or compare table
- Waterpik's own store showed all four colors sold out on October 16, 2026
- The 99.9 percent plaque bacteria claim is backed by a laboratory study on file, not a published clinical trial
At a glance
| Type | Countertop water flosser, corded electric |
|---|---|
| Reservoir | 22 oz (651 ml), covered, removable; 90-plus seconds of use |
| Pressure settings | 10; PSI range not listed by the vendor |
| Pulses per minute | 1,400 |
| Flow rate | 13 oz (384 ml) per minute |
| Modes | 2: Floss and Hydro-Pulse Massage |
| Timer | 1-minute timer with 30-second pacer |
| Tips included | 7: 4 Precision JT-100E, 1 Orthodontic OD-100E, 1 Pik Pocket PP-100E, 1 Plaque Seeker PS-100E |
| Size and weight | 10.35 in H x 4.70 in W x 3.80 in D with tip; 1.46 lb (0.662 kg); 52 in cord |
| Power | 120 VAC / 60 Hz, North America only |
| Warranty | 3-year (36-month) limited warranty |
| Price | $99.99 MSRP as of October 16, 2026 |
| Pricing note | $99.99 MSRP on waterpik.com; the Waterpik store listed all four colors (WP-660 White, WP-662 Black, WP-663 Blue, WP-667 Gray) as sold out when checked October 16, 2026 |
What the Waterpik Aquarius actually is
The Aquarius WP-660 is a countertop oral irrigator: a corded base with a 22 oz reservoir, a pump that pulses water 1,400 times per minute, and a hose to a handle that takes clip-on tips. It cleans between teeth and along the gumline with water, not bristles.
It is not a toothbrush and does not claim to be one. It sits beside a brush such as the Oral-B iO Series 5 or the Philips Sonicare 9900 Prestige, covering the step the ADA calls interdental cleaning.
Waterpik also sells a WP-670 Aquarius Professional that is the same machine with chrome accents and a different tip mix. This review covers the WP-660 and notes the WP-670 differences where they matter.
Every figure here was read from waterpik.com on October 16, 2026. This is a documentation review; the unit was not used. How we grade explains the method.
Who the Aquarius is best for
The tip list, the studies Waterpik cites and the ADA's guidance point to specific users.
- People with braces: the Orthodontic tip is in the box and Waterpik cites Sharma 2008 for plaque removal around brackets
- People with implants, crowns or bridges: the Plaque Seeker tip is included and Waterpik cites a 2014 Tufts study for implant gum health
- People with periodontal pockets: the Pik Pocket tip delivers low-pressure rinsing, per the tip's name and Waterpik's description
- Anyone who does not floss consistently and has counter space and an outlet by the sink
- Households sharing one unit: four Precision tips are included, enough for several users with their own tips
- Buyers who want the longest warranty in the category: 36 months
Who should skip it
The spec sheet rules it out for three groups.
- Small bathrooms without an outlet near the sink: the unit is 10.35 in tall with a 52 in cord
- Travelers: 120 V / 60 Hz, North America only, and 1.46 lb plus a 22 oz reservoir
- People who want a published PSI range to compare against other brands: Waterpik does not list one
Pressure, pulses and the reservoir, per the spec sheet
Ten pressure settings are stated. The PSI range is not listed on the product page or the compare table, which is the single most notable gap in otherwise complete documentation. Pulse rate is 1,400 per minute and flow rate is 13 oz (384 ml) per minute.
The reservoir holds 22 oz (651 ml), is covered and removable, and gives 90-plus seconds of use. At 13 oz per minute, that arithmetic works: 22 oz lasts about 100 seconds at full flow, which is editorial math from Waterpik's two figures.
Two modes are listed: Floss and Hydro-Pulse Massage. The handle has an on/off slider and a 360-degree rotating tip. There is an LED function indicator and no LCD display.
The built-in timer runs one minute with a 30-second pacer, prompting a switch from the upper to the lower arch. The ADA recommends cleaning between teeth once a day; the timer structures that minute.
The seven tips and what each is for
Waterpik lists the tips by part number, which is more than most vendors do. In the WP-660 box: four Precision tips (JT-100E), one Orthodontic tip (OD-100E), one Pik Pocket tip (PP-100E) and one Plaque Seeker tip (PS-100E).
The Precision tip is the general-purpose jet. The Orthodontic tip adds a tapered brush for brackets and wires. The Plaque Seeker has bristles for implants, crowns and bridges. The Pik Pocket is a soft rubber tip for low-pressure delivery into periodontal pockets.
The WP-670 Aquarius Professional swaps one Precision tip for a Toothbrush tip (TB-100E). Neither model includes the Tongue Cleaner or Implant Denture tips, which are sold separately.
Waterpik does not state a replacement interval for tips on this page. The ADA's guidance on not reusing floss does not translate directly to tips; follow the owner's manual.
The ADA Seal and the studies Waterpik cites
The product page states the Aquarius is accepted by the American Dental Association for safety and effectiveness, and the Seal graphic reads that it helps remove plaque along the gumline and between teeth and helps prevent and reduce gingivitis.
For powered interdental cleaners and oral irrigators, the ADA's criteria require evidence that the device plus brushing is more effective than brushing alone for plaque and gingivitis, that components are safe in the mouth, and that unsupervised use will not harm oral tissues or restorations. The Seal runs five years and is awarded by the Council on Scientific Affairs.
Waterpik's claims and their backing, as footnoted on the page: up to 99.9 percent of plaque bacteria removed from treated areas (laboratory study, data on file); up to 2 times as effective as string floss for plaque and gum health (Barnes 2005); up to 2 times for gum health around implants with the Plaque Seeker tip (Tufts 2014); up to 3 times for plaque around braces with the Orthodontic tip (Sharma 2008).
One caution: the ADA's own floss topic page cites a 2019 Cochrane review that found evidence for oral irrigators limited and inconsistent. The Seal and the Cochrane summary are both true at once. The Seal says the device is safe and adds benefit over brushing alone; Cochrane says the comparative evidence base is thin. Neither is medical advice; ask your dentist.
Size, power and placement
Published dimensions: 10.35 in (26.29 cm) tall with the tip, 4.70 in (11.94 cm) wide and 3.80 in (9.65 cm) deep at the base. Unit weight 1.46 lb (0.662 kg); shipping weight 2.00 lb. Power cord 52 in.
Power is corded, 120 VAC / 60 Hz, North America only. There is no battery. That makes it cheaper and more powerful than a cordless unit, and it means it lives on the counter.
Features listed as No on the spec table: magnetic handle, chrome accents (the WP-670 has them), multiple user profiles, SmartAdvance mode and LCD display. Waterpik is unusually candid about what a model lacks, which is useful when comparing up the range.
How the price is structured (as of October 2026)
MSRP is $99.99 on the Waterpik product page and compare table. The WP-670 Aquarius Professional is $109.99 for chrome accents and the Toothbrush tip swap.
The Waterpik store page for the White WP-660 showed $99.99 and a title referencing an AQUARIUS20 code for $20 off at checkout, but every color (White WP-660, Black WP-662, Blue WP-663, Gray WP-667) was marked sold out on October 16, 2026. Retailer stock may differ; this review does not quote retailer prices.
Running cost is tips. Waterpik sells replacement tip packs; prices were not read for this review. There is no battery to age out, which matters for a device with a three-year warranty.
Five Cent Shave has no affiliate relationship with Waterpik at the time of writing; see our disclosure.
Ease of use: what the 4.0 is built from
Ten settings, two modes, a slider and a timer are simple to operate. The deductions are physical: a 10-inch corded unit needs counter space and an outlet, the 22 oz reservoir needs filling and emptying, and the PSI range is not published to guide setting choice.
The 360-degree rotating tip and 52-inch cord are the two usability specs Waterpik does publish, and both help.
Features: what the 4.2 is built from
Seven tips, 10 settings, 1,400 pulses, a timer with pacer, a massage mode and a covered reservoir cover the practical feature set for a countertop irrigator. The score stops at 4.2 because the Aquarius has no user profiles, no display and no SmartAdvance mode, all of which Waterpik lists as No on its own table.
Value: what the 4.3 is built from
At $99.99 MSRP, the Aquarius costs the same as the Oral-B iO Series 5 and a quarter of the Sonicare 9900 Prestige, and it comes with a longer warranty and a published owner rating from nearly 3,000 reviews. The deduction is for the stock situation on Waterpik's own store and the unlisted PSI range.
Support and warranty: what the 4.5 is built from
A three-year (36-month) limited warranty, stated on the product page, the compare table and the store listing, is the longest in our oral care set. Oral-B and Philips each state two years.
Waterpik refers to the owner's manual for details and lists no money-back window on the product page. The grade is the highest in the set because of the warranty length and the completeness of the published documentation.
What verified owners report
Waterpik's compare table publishes an owner rating value for each model. For the WP-660 it showed 4.6419 out of 5 from 2,893 reviews on October 16, 2026; the WP-670 showed 4.6603 from 1,210. Those are the largest published samples in this set.
The product page's own review section was empty when read, so no individual review text or theme is quoted here. The compare table figures are the evidence.
For context across the set: the Oral-B iO Series 5 page showed 4.5 from 302 reviews, the Oral-B iO Series 9 3.9 from 328, and the Philips page rendered verified-buyer reviews without a readable aggregate.
Alternatives
Choose the Waterpik WP-670 Aquarius Professional if you want chrome trim and a Toothbrush tip in the box for $10 more. Otherwise choose the WP-660 if you want four Precision tips and the same machine.
Choose a cordless Waterpik if you have no counter space or travel with it. Waterpik's compare pages list cordless models with smaller reservoirs; this review did not read them.
Choose a better toothbrush first if your issue is brushing technique rather than interdental cleaning. The Oral-B iO Series 5 at $99.99 and the Sonicare 9900 Prestige both carry pressure sensing; the ADA's order is brush twice a day, clean between once a day.
All of these are graded in our oral care section.
Bottom line
The Waterpik Aquarius WP-660 is the product in this set whose vendor tells you the most: every capacity, dimension, tip and claim is published with a number or a named study, and the warranty is three years. The ADA acceptance statement and the 4.64 rating from 2,893 owners back it up.
Its limits are physical and honest: corded, countertop, North America only, PSI unlisted, and sold out on Waterpik's own store when checked. If you need between-the-teeth cleaning and have the counter space, this is the reference product at $99.99.
This is a documentation review. We read Waterpik's pages and the ADA's criteria; nobody here ran the machine.
Buy it if
- Your dentist has told you to clean between your teeth and floss is not happening. The ADA recommends interdental cleaning once a day; a water flosser is one accepted way to do it.
- You wear braces or have implants. Waterpik includes an Orthodontic tip and a Plaque Seeker tip and cites studies for both cases.
- You want the longest warranty in the category. 36 months, per the product page.
- You want owner evidence at scale. 4.64 out of 5 from 2,893 reviews on Waterpik's own compare page.
Skip it if
- You have no outlet or counter space by the sink. This is a 10-inch corded unit, not a cordless handle.
- You travel outside North America with it. 120 V / 60 Hz only, per the spec sheet.
- You expect it to replace brushing. The ADA frames interdental cleaning as an addition to brushing twice a day, not a substitute.
Frequently asked
Is the Waterpik Aquarius ADA accepted?
Waterpik's product page states the Aquarius is accepted by the American Dental Association for safety and effectiveness, and the Seal graphic says it helps remove plaque along the gumline and between teeth and helps prevent and reduce gingivitis. The compare table does not repeat the Seal row, so confirm on the ADA directory.
How many tips come with the Waterpik Aquarius WP-660?
Seven, per the product page and compare table on October 16, 2026: four Precision tips (JT-100E), one Orthodontic tip (OD-100E), one Pik Pocket tip (PP-100E) and one Plaque Seeker tip (PS-100E). The WP-670 swaps one Precision tip for a Toothbrush tip.
How long does the Aquarius reservoir last?
Waterpik states 90-plus seconds of use from the 22 oz (651 ml) reservoir at a flow rate of 13 oz per minute. The built-in timer runs one minute with a 30-second pacer, so one fill covers a full timed session with margin.
What is the difference between the Waterpik Aquarius WP-660 and WP-670?
Per Waterpik's compare table, the WP-670 Aquarius Professional ($109.99) adds chrome accents and a Toothbrush tip in place of one Precision tip. Reservoir, 10 settings, 1,400 pulses, timer, dimensions and the 36-month warranty are identical to the WP-660 ($99.99).
Does a water flosser replace string floss?
The ADA says interdental cleaning once a day is essential and lists floss or another interdental cleaner. A 2019 Cochrane review the ADA cites found evidence for oral irrigators limited and inconsistent. Waterpik cites studies showing advantages over string floss. Ask your dentist which tool fits your mouth.
How much does the Waterpik Aquarius cost and is it in stock?
MSRP is $99.99 on waterpik.com as of October 16, 2026. The Waterpik store page listed the same price with a $20 checkout code in its title, but all four colors were marked sold out when read. Retail availability varies; the figure here is a dated snapshot.
Sources
- Waterpik Aquarius WP-660 product page (full specifications, tips, warranty, ADA statement, clinical claims) - checked October 16, 2026
- Waterpik compare table WP-670 vs WP-660 (prices, owner ratings, tip counts) - checked October 16, 2026
- Waterpik store listing, Aquarius White (stock status, colors) - checked October 16, 2026
- ADA oral health topic: Floss and interdental cleaners (oral irrigator evidence, Seal criteria) - checked October 16, 2026
Update history
- October 16, 2026 - First documentation review. Specifications, warranty, ADA statement, prices and owner ratings read from waterpik.com and store.waterpik.com on October 16, 2026.
Visit Waterpik Aquarius (WP-660)
We have no affiliate relationship with this vendor. Link goes to the official site.