Waterpik Reviews: The Waterpik Aquarius Professional Water Flosser (WP-660 & WP-670)

by | Apr 5, 2017 | Product Reviews, Waterpik Reviews

The Waterpik Aquarius Water Flosser, WP-660 (and WP-670), is hands down the most popular product on the market for oral irrigators. The reason for this is quite obvious – it is the latest countertop product of the brand which created the market and without a doubt has the strongest tradition in it. The Waterpik Aquarius Professional water flosser is Waterpik’s attempt to redesign and modernize their countertop product line, which dates back to 1967. Judging by the huge commercial success of the product they have managed to do that. But is this success founded on the quality of the product or just the result of the popularity of the brand? This is the question Anna and I will try to answer in the following Waterpik Aquarius review in as much depth as possible:

  • Usefulness 75%
  • Design 65%
  • Reliability 85%
  • Vlaue for money 75%


  • It does its oral health care job very well
  • Easy enough to use to include in your daily routine
  • The Waterpik Aquarius is good looking compared to most water flossers
  • It is reliable and sturdy: arguably less so than older Waterpik models, yet quite a bit more than most competitor products


  • Besides looks, it isn’t much of an improvement over older Waterpik models
  • It has minor design flaws that could become a nuisance: hard to reach replacement tips; too firm on/off switch; a bit too lightweight when empty; lid permanently attached to the machine and gets in the way;
Waterpik Aquarius Professional Water Flosser WP-660


Let’s start with what’s most important – the Waterpik 660 does its oral hygiene job wonderfully.

Waterpik as a company takes a lot of pride in the fact that the effectiveness of their products has been proven in multiple clinical trials. The Aquarius is no exception: it removes up to 99.9% of plaque biofilm – significantly more than string floss. It is also very beneficial for overall gum health and reducing gingivitis.

It has 10 pressure settings (going from 10psi to 100psi), which gives users a lot of freedom. You can choose exactly the pressure level at which you feel most comfortable and slowly increase it with time as your gums become healthier and less sensitive.

Additional info: water pressure concerns

A few users on Amazon claim that the Aquarius has a lower water pressure than older models and recommend the Classic (WP-60) or the Classic Professional water flosser (WP-72) as an alternative. Yet, according to Waterpik, this is not the case – WP-660 and 670 have a top pressure of 100psi, while the WP-60 and WP-72 have a top pressure of 90psi. While I have not tested the Waterpik Classic and Waterpik Classic Professional water flossers, I doubt Waterpik would lie about something as easily testable. Moreover, if the top pressure of the Waterpik Aquarius was any stronger it would actually hurt my gums. So, if you feel the pressure of your Aquarius is insufficient even at the highest setting right out of the box, you should consider the possibility that your unit is faulty.

All in all, if you are thinking about getting the Waterpik Aquarius Professional water flosser, you shouldn’t worry about the water pressure being weak.

The Waterpik Aquarius Professional water flosser is easily included in your daily routine. Don’t forget that when it comes to oral health, habit is what is most important if you want long term results. This was the main problem I had with dental floss and the main reason I fell in love with water flossing – it’s easier, quicker and much more pleasant.

The Waterpik Aquarius Professional comes with multiple features for users that have specific needs and want to make the most out of the product.

It comes with 7 replacement tips out of the box:

Waterpik Aquarius (WP-660 & 670) Replacement Tips
  • Three Classic Jet Tips so that up to three people can have a personal tip.
  • One Plaque Seeker Tip with three tufts of bristles to help cleaning dental work like implants, crowns or bridges.
  • One Pik Pocket Tip for reaching deep into periodontal pockets (you need to use lower water pressure).
  • One Toothbrush Tip that you can use to brush your teeth during flossing. (We don’t recommend brushing during, the toothpaste washes away quickly).
  • One Orthodontic Tip with bristles for cleaning braces.

Besides the regular Floss Mode, the device has a new Hydro-Pulse Massage mode specifically designed for massaging your gums. To be honest, I thought this was a gimmicky feature and never used it. Yet, Anna said the slower pulses of water could actually be more efficient at stimulating blood circulation in your gums than the regular almost constant stream of water. This might mean that the massage mode is benefitial to people that have problematic gums.

The rubber feet are adequate to hold the water flosser firmly on your counter, which is good since the whole machine is relatively light at 1.5 pounds. This is not much of a problem when it’s full, but when it’s empty a stronger tug on the hose could bring the flosser to the ground. This might damage it permanently. (I haven’t managed to do so yet and don’t plan to run that test, sorry dear reader.)

Additional info: Waterpik Aquarius water flosser (wp-660c)

Maybe you’ve seen somewhere the product number of the Waterpik Aquarius written with an additional letter: WP-660c instead of WP-660. This shouldn’t worry you – there is no difference between the Waterpik Aquarius WP-660 and WP-660c, they are one and the same product.  If you take a look at the bottom of the water flosser, you’ll see that WP-660c is printed. Yet, Waterpik uses the shorter WP-660 when they are talking about their product (e.g. on their website, in the manual, etc.). Because of this, we decided to use WP-660 in our reviews as well.

The tank holds enough water for 90 seconds of use. Waterpik has helpfully included a 1 minute timer with a 30s pacer in the Waterpik Aquarius to remind you when to move on to the other half of your mouth. (On average 1 minute of water flossing per session should be enough.) Despite the fact that a lot of users find the timer useless, I think the 2x30s intervals help you manage your time so that you don’t run out of water before you are done flossing.

The water tank is removable, which makes it easy to fill or clean. I don’t need to remove it when I fill it because the faucet in our bathroom is flexible, yet I imagine this feature is a must for people with a more traditional sink. One of the most common complaints about the design of the product is that the lid is permanently attached to the body and gets in the way of removing and placing the tank easily.

Waterpik Aquarius (WP-660) replacement tip storage

Another common complaint is the fact that the replacement tip storage is inside the flosser, next to the tank, which makes it hard to reach if the tank is not removed. This is true especially if you have bigger hands. I guess the thinking of the designers was that if you want to use the Waterpik Aquarius Professional you would have to remove the tank anyway to fill it. My experience, however, proves that this is not always the case and putting the tip storage there was not a great design decision. In my opinion many other water flossers like the cheaper and older Waterpik Ultra water flosser (WP-100) model handle replacement tip storage better.

The designer’s thinking that people will remove the water tank before using the Waterpik Aquarius is obvious from another design decision: the water volume measuring gauge is printed on the inside of the water tank from the side of the lid. This makes the gauge impossible to read if the tank is not removed.

The tip storage can accommodate only two tips, (less than the Waterpik Ultra water flosser, WP-100). This is usually enough if only one person is using the device. Yet, if the whole family is using the flosser, it might prove insufficient.

Users also complain that using the Waterpik Aquarius is messy. Yet, using it with proper technique (lean over the sink, open mouth slightly, turn on when the tip is in your mouth) should solve this problem. If you prefer having your mouth opened while cleaning for some reason you should get a cordless water flosser and use it in the shower to avoid any messiness.

My biggest problem with the Waterpik Aquarius and electric water flossers in general, is that they are loud. Since our bathroom is close to the bedroom and Anna tends to go to bed earlier than me, using it is not an option while she is sleeping. I’ve even taken it to the kitchen sink a couple of times to be able to floss without waking her. Nonetheless, if your bathroom is more isolated or you tend to go to bed at more normal hours, the noise might not be an issue for you. If you think the noise will be a problem, you could try a non-electric water flosser.

All in all, we give the Waterpik Aquarius WP-660 7.5 out of 10 for usefulness. It could have gotten a perfect score if it wasn’t for the minor inconveniences that the lid and the tip storage present as well as its loudness.

WP-660 & WP-670: DESIGN

Waterpik Aquarius WP-670

It is obvious that Waterpik is trying to modernize the appearance of their products. The WP-660 and WP-670 series are a prime example of this effort, especially when you see them next to the WP-100 and WP-72. It might seem that looks are not vital for an oral healthcare product, yet I think this is not correct and I don’t say this out of vanity. Maybe to a professional dentist or to a very disciplined user looks don’t matter. If you are a more casual flosser, however, you might find it much easier to bring yourself to use the device every day if you think it looks sleek and cool. I love products that make me feel a bit like a child with a shiny, fancy toy.

Sadly, I wouldn’t say the Aquarius manages to invoke such feelings in me. I just feel that it looks a lot more like a blender rather than some high-tech device out of the future. This is the main reason I honestly prefer the Jetpik JP-200 Elite over this, despite the fact that the Jetpik has many other issues. Jetpik water flossers tend to be less reliable than Waterpik water flossers – you can read more about this in our Jetpik vs Waterpik buyers guide.

Nonetheless, the Aquarius is definitely a step in the right design direction for Waterpik as a manufacturer.

The introduction of the Waterpik Aquarius Professional Designer Series water flosser (the WP-670 series) helps in this regard a bit, mainly because you can choose the color that excites your inner child the most. Moreover, the more modern color options make it seem a bit less like a kitchen appliance.

The Waterpik Aquarius Professional Designer Series (WP-670) goes as follows:

White (WP-670);     Black (WP-672);     Blue (WP-673);      Pink (WP-674);     Orchid (WP-675);     Teal (WP-676);

The bad news is that you would have to pay extra for the ability to choose your color and to have glossy buttons (this is literally the only difference in WP-660 vs WP-670). The practical person in me can’t help but think it’s not worth it.
We give the Waterpik Aquarius Professional water flosser a 6.5 out of 10 for design. It is better looking than the average countertop water flosser on the market, nonetheless, it’s not going to win any design awards anytime soon.


Waterpik products as a whole have a track record of being very long lasting. It is not uncommon to read about people that have just changed their old Waterpik water flosser that they’ve had for many years for a new model. Sadly, it is also quite common to read opinions by the same people that the old products were of higher built quality and as a result – longer lasting. I can’t help but think this is an overwhelming criticism of modern home appliances as a whole, rather than specifically Waterpik or the Aquarius.

The good old days aside, I would definitely not call the Aquarius a flimsy product. The three-year warranty it comes with supports this statement. In fact, it wouldn’t be far-fetched to call the Aquarius along with most other Waterpik water flossers the most reliable flosser on the market. The main complaint about most other brands is not that they don’t clean well enough, but that they don’t last long enough.

That being said, there are some issues that need addressing:

The most common complaint is that after some usage water begins to leak from under the tank or more rarely from the base of the hose.

The leak from the base of the hose seems to come up only when the hose is not properly and firmly connected to the body. It detaches so that you can replace it when the hose get’s too old or breaks. Simply adjusting it and tightening it seems to fix the problem.

The leak from below the tank, however, seems to be a bigger and more common problem.The reason seems to be the low quality of the material that seals the water tank to the lower part of the device (called an O-ring). It feels more like a rubberized plastic rather than let’s say a high-quality rubber or silicone. Moreover, it seems it relies mostly on the weight of the tank and the water to create a tight fit. This means that when the device ages, any deformation in the O-ring will result in leaks of various degrees. Worse of all, the warranty of the product doesn’t seem to cover this problem.

Additional info: fixing leaks DIY style

Some users manage to fix this kind of leaks by gluing the tank to the pump (silicone would probably be your best option). However, we cannot really recommend this method since it will most definitely void your warranty. Moreover, not being able to remove the tank means you need to put the whole unit under the sink or use something else to fill it with (a bottle, etc.). It also makes it much harder to clean.

In any case, making sure to press the tank firmly when you use it and to empty it from leftover water when you are done will make sure minor leaks are no big deal.

In order to have their hose resemble a spring and help it go back in place easily, Waterpik has decided to use a harder plastic material. This means that twisting it a lot for some reason might permanently damage it. In most cases this wouldn’t matter. Yet, I can imagine how having young children use the device could potentially end badly for your Aquarius Waterpik water flosser.

When it comes to cleaning and maintenance, the easiest thing to do is to place the tank in your dishwasher. Like with other water flossers, running the machine with a white vinegar solution once every few months will prevent the appearance of mildew inside the tubing.

Despite being one of the most reliable products on the countertop water flosser market, we cannot give the Waterpik Aquarius Professional water flosser a full 10. We give it 8.5/10 mainly because of its o-ring seal problem.


Back to our question: is the commercial success of the Waterpik Aquarius Professional water flosser, WP-660, a result of the quality of the machine or the fame of the brand?

I would say a bit of both. The Aquarius is a high-quality product by all accounts, one of the most reliable and useful machines on the market. Yet, it doesn’t bring anything groundbreaking to the table and I doubt it would have been the #1 best-selling flosser if it wasn’t made by Waterpik.

The lack of innovation and the not-good-enough design are a bit of a turn-off for me. As I mentioned I prefer the Jetpik Elite (JP-200) to the Aquarius because of this reason. This is also the reason why in our Best Water Flosser buyers guide we chose Waterpik Aquarius as the best countertop water flosser, but Jetpik JP200 Elite as the best overall.

Nonetheless, when Anna recommends a water flosser to her patients she always recommends Waterpik products (most commonly the Aquarius or Ultra). She does that simply because of their superior reliability, the brand’s background in the industry and the fact that their claims are tested in scientific studies.

When it comes to chosing a water flosser, Waterpik is the safe choice and so is the Aquarius.

Waterpik Aquarius (WP-660) in black and white