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Waterpik Aquarius WP-660 Review: Would Owners Buy It Again?

Disclosure: As an Amazon Associate I earn from qualifying purchases. If you buy through links on this page we may earn a commission at no extra cost to you. How this review was made: We did not test this water flosser in person. This verdict is based on our analysis of Reddit discussions, expert reviews and owner reports, all listed at the end of this article. Our method.

Depends

Effective and well-loved, but register that warranty

The Aquarius is the water flosser Reddit mentions most, and dentists often recommend it by name. Owners like the 10 pressure levels and big tank. The catch is reliability: some owners report leaks from the handle or base within months, and one says theirs stopped working reliably after 16 months. The 3-year warranty helps a lot, so keep your receipt.

Check current price on Amazon → Prices and availability change often, so we don't list them here.

Buy it again if you…

  • want a countertop flosser with lots of pressure control
  • have braces, implants or bridges (it includes specialty tips)
  • don't mind a corded unit on the bathroom counter
  • will register the 3-year warranty

Skip it if you…

  • have very little counter space
  • want something quiet for early mornings
  • want a cordless unit for travel

This review summarizes user experiences and is not dental or medical advice. Ask your dentist whether a water flosser is right for you.

The Waterpik Aquarius WP-660 is a countertop water flosser with a 22 oz tank, 10 pressure settings, a massage mode and seven different tips. It's been sold for years, so there's lots of owner feedback.

What owners say, at a glance

#1most-mentioned water flosser on RedditRedditConsumer's 2026 roundup
3 yearsmanufacturer warrantyLonger than most rivals
72 dBnoise at maximum pressureMeasured by Electric Teeth
Cleaning results
Strong praise
Pressure control
Strong praise
Leaks over time
Common complaint
Noise
Mixed
Counter space
Mixed

Bars show our editorial summary of how consistently owners praise or complain about each area across all sources — not a lab measurement.

The key specs

Tank22 oz (651 ml)
Pressure10 settings, about 10–100 PSI
ModesFloss and Massage
Tips included7, including orthodontic, plaque-seeker and pik-pocket tips
Timer1 minute, with a 30-second pacer
Warranty3 years

What owners love

Dentists recommend it.On Reddit, one user's dentist emailed them specifically recommending the Aquarius. It's the most-mentioned model in Reddit water-flosser discussions.
Lots of pressure control.Owners like being able to start low and build up. Many find a middle setting is plenty.
A big tank and useful tips.The 22 oz tank lasts a full session, and the specialty tips suit braces and dental work.
Less mess than older models.Reviewed's tester found it didn't spray water everywhere, unlike their previous flosser.

What owners complain about

Leaks.This is the main complaint. Reddit users report leaks from the handle or base within months, and some suspect quality varies between batches. One owner says their unit stopped working reliably after 16 months.
It's loud.Electric Teeth measured 72 dB at maximum pressure. It's not ideal when others are sleeping.
It takes up space.It's a corded countertop unit, and some owners find tip storage awkward.

How it holds up after months of use

This is why we give it a Depends rather than a Repeat. Plenty of owners use theirs for years, but leak reports are frequent enough that some Reddit users switched to cordless models or simpler designs. The 3-year warranty is the safety net. Waterpik also sells replacement parts, and many leaks come from a tip or handle that isn't fully seated.

Tips from owners

  • Make sure the tip clicks into place. A loose tip is a common cause of leaks.
  • Start on setting 1–3 and increase over a few weeks.
  • Run a vinegar-and-water cycle now and then to clear mineral buildup.
  • Replace tips every 3–6 months.
  • Register the product so the 3-year warranty is easy to use.

Pros and cons

What owners love

  • Most-recommended water flosser among Reddit users
  • 10 pressure settings and 7 tips
  • Large 22 oz tank
  • Built-in timer and pacer
  • 3-year warranty

What owners complain about

  • Leak reports within months for some owners
  • Loud at higher settings
  • Corded and takes up counter space
  • Replacement tips are an ongoing cost

Other options owners compare

Owners who switched away usually went for one of these.

ModelTypeConsider it if…
Waterpik Aquarius WP-660 (this review)CountertopYou want maximum pressure control at homeSee on Amazon
Philips Sonicare Power Flosser 3000CordlessYou want cordless and easier to storeSee on Amazon
Waterpik Cordless AdvancedCordlessYou want Waterpik but portable and quieterSee on Amazon

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Frequently asked questions

Why is my Waterpik leaking?

The most common cause is a tip that isn't fully clicked in. If it leaks from the base or handle, contact Waterpik, since the WP-660 has a 3-year warranty.

What pressure setting should I use?

Start low (1–3) and build up. Many owners find a middle setting is enough.

How loud is it?

Electric Teeth measured 72 dB at maximum pressure.

How long does a Waterpik last?

Many owners use theirs for years, but some report leaks within months. The 3-year warranty covers defects.

Sources we analyzed

Figures reflect each source as of September 29, 2026 and may change. We summarize owner feedback in our own words and do not reproduce retailer reviews.