Waterpik Aquarius WP-660 Review

Waterpik Aquarius Review: Quick Verdict

Water flossing is now part of my daily routine. I noticed a difference in how clean my teeth feel, and it’s good at dislodging food.

The noise is what I wasn’t expecting. It’s not a dealbreaker for me, but it’s the reason I’d look elsewhere if I were buying today.

What Changed When I Started Using It

I added the Aquarius to my routine rather than replacing anything. I still use string floss, and I use the Waterpik daily on top of it. Three things stood out:

• My teeth feel cleaner. It’s the most immediate difference.
• It dislodges food. It clears out bits that brushing and floss didn’t get.
• My dentist noticed. That’s the result I care about most, even though it’s only one person’s experience.

I use a medium setting, between 4 and 7, which works well for me. Waterpik’s Aquarius goes up to 10, and it says its 9+ range is where it aims for deep cleaning, but starting lower is an easier way in.

How Loud Is the Waterpik Aquarius?

Louder than I expected. It’s a motor and a pump on your bathroom counter, and it makes itself known. If you floss late at night or early in the morning around other people, it’s worth thinking about.

Waterpik does offer a quieter option. In its own comparison, the Promax WF-23 is the only countertop model listed with QuietPulse noise-control technology, which it recommends for shared spaces.

Water Flosser vs. String Floss: What the Research Says

Waterpik says the Aquarius is “up to 2X as effective” as string floss for plaque and gum health. Independent systematic reviews are more modest:

• A 2025 meta-analysis of 18 randomized trials found that in people without braces, water jets gave no additional plaque improvement over flossing, a slight improvement in gum bleeding, and similar gingival scores.
• A 2023 meta-analysis of 16 trials and 1,258 people with gingivitis found water-based tools plus brushing gave comparable plaque and bleeding results to brushing and flossing. Most studies that asked about preference found people favored the powered tools.
• A 2023 systematic review of seven trials found most studies favored water flossers for plaque, and it concluded they’re an effective alternative to floss. It didn’t pool the results.
• For braces, a 2024 meta-analysis found better plaque and bleeding scores when a water jet was added to brushing, though only four studies were pooled, and risk of bias varied.

So the fair summary is that a water flosser works about as well as floss for most people, with a small edge on gum bleeding. The other advantage is that you’re more likely to keep doing something that you find easier. I use both, and that’s a personal choice rather than something this research proves is necessary.

The “99.9% of plaque bacteria” claim on the box comes from a laboratory study, by Waterpik’s own footnote, so it doesn’t describe what happens in your mouth.

Aquarius vs. Promax

If noise bothers you, this is the comparison that matters. The Promax costs more at list price, but Amazon has sold it for about $120.

I haven’t used the Promax, so I can’t tell you how much quieter it is in practice. For anyone in my position, though, it’s the first one I’d check. If you want no cord, Waterpik’s ION (WF-12) is a rechargeable countertop model.

How to Use a Waterpik

If you’re new to water flossing, a few habits make it much less messy:

1. Fill the reservoir with lukewarm water.
2. Start at a low setting and work up as you get comfortable.
3. Lean over the sink, put the tip in your mouth, and only then turn the water on.
4. Keep your lips mostly closed, and let the water run out into the sink.
5. Follow the gumline and pause between teeth, working from back to front.

Is the Waterpik Aquarius Worth It?

Water flossing is worth it to me, and the Aquarius does it well at a fair price. I’d buy another water flosser, but I’d choose a quieter one.

Buy it if you want a proven countertop flosser at about $100, you have braces or implants and want the extra tips, or noise doesn’t matter in your home.

Skip it if you floss while others are sleeping, you have little counter space, or you need something for travel.

Waterpik Aquarius FAQ