I wanted cleaner, better-tasting water without plastic bottles – so I tried this undersink filter in my kitchen

From removing contaminants to improving taste, there are lots of benefits to installing an under-sink water filter at home, which is why I've been hankering after one for years. But with most reverse osmosis systems costing over a grand, I found it hard to commit to the investment.

So, when the opportunity came to test the Waterdrop X16 Premium 1600 Reverse Osmosis System (available on Waterdrop) , I had to give it a go. The filter removes 99.9% of bacteria in the water through an 11-stage filtration system and adds calcium and magnesium back for a balanced mineral profile.

Below, I've explained everything you need to know about the system, including how easy it was to install, my water quality test results and, the big one, whether it's really worth the money.

Waterdrop X16 Premium 1600: Specs

Waterdrop X16 Premium 1600: installing the filter

While the installation video doesn't look massively complicated for seasoned DIYers, I decided to hand the job over to a professional to make matters easier – especially since it involved drilling into our granite worktop, which we were terrified would crack.

Before the plumber came round, we had to think about where we would store the system, as the space under our sink was currently occupied by our household bins. We ended up reconfiguring our kitchen cabinets and designing a specific built-in slot for it to go into. The unit measures 46.2L x 15.9W x 42.5H cm and you'll need at least two inches of clearance around it.

Next up, we had to think about where to position the faucet on the sink. I was initially worried that an additional tap would make the sink look cluttered, but the sleek chrome finish and black digital display blend in surprisingly well with our worktops.

The filter comes with the system, drain water tube, smart faucet, power adaptor, feed water adaptor, lock clips, Teflon tape and drain saddle.

It took our plumber two to three hours to fit the tap and system, and while he wouldn't describe the job as hard, he did run into a problem with one of the provided connection pipes, which wasn't perfectly perpendicular and created a leak. However, the problem was solved after he cut it himself.

Waterdrop X16 Premium 1600: using the filter

Design and ergonomics:

Overall, I'm very happy with the design and ergonomics of the faucet. The chrome finish blends in nicely next to my existing tap and kitchen design, and it's satisfying to press on and off by clicking the circular head, which can be turned left and right to adjust the flow rate. As I would expect from a premium product, the build feels high quality and sturdy.

Flow:

Waterdrop claims that the faucet can fill a glass within 10 seconds, and I can confirm that it has an impressively fast flow. By spinning the dial, you can adjust the flow rate to fill between 200 and 2,000 millilitres of water, which is pretty handy when it comes to baking and cooking with measurements and saves you having to turn it off yourself.

Temperature:

The water comes out at room temperature and while this suits me perfectly, those who prefer ice-cold water might want to install a cooling system instead, like the one below.

Taste:

I personally love the taste of our water now, but I have had mixed feedback from the other members of my household, who said it has taken them a while to get used to it and compared it to Volvic. It definitely has more of a soft, minerally flavour than regular tap water, but I quite enjoy it. Either way, we all agree that the taste is worth it for the benefit of cleaner water and use it every day.

Ongoing costs:

You'll need to replace the filters as follows:

• F2 filter – up to 6 months or 550 gallons (£29.99)
• F1A filter – up to 12 months or 1,100 gallons (£34.99)
• X16-F3 RO filter – up to 24 months or 2,200 gallons (£179.99)

You won't need to worry about remembering this, though, as the digital display alerts you when it's time for a replacement.

Note: Our tap may be slightly noisier as we have a heat pump next door to our kitchen.

Waterdrop X16 Premium 1600: testing the filter

To find out whether it lived up to the claims, I used these water-testing strips from Amazon to compare the filtered water with my regular tap water.

Here are the results:

The biggest change was a massive reduction in my water hardness. As the minerals were removed by the reverse osmosis process, there was also a reduction in carbonate, pH and total alkalinity.

The TDS (Total Dissolved Solids) of the filtered water is 25mg per litre, which represents how many dissolved particles are in the water. This was far less than there was before, indicating that the filter isn't doing much remineralisation, which accounts for the reduction in carbonate, pH and total alkalinity.

I found the claim that the filter creates a pH of 7.5± to be false. In the test, it indicated a lower pH than before of around 6.8, compared to 7.2 in the unfiltered water. This isn't a problem, as the UK drinking guidance recommends a range of pH 6.5–9.5, but it just wasn't as advertised.

However, the thing that I'm really interested in – removing microplastics, PFAS and other heavy metals – cannot be detected by my testing strips and requires a specialist lab. These are some of the most important contaminants that a reverse osmosis system can remove.

In summary, the filter proved effective at softening my water, and removing minerals and other contaminants, but Waterdrop overstates the remineralisation.

Waterdrop X16 Premium 1600: final verdict

To conclude, I'm super impressed with this filter in terms of its design, performance and how well it softened my water. It tastes good, looks sleek, and once you've got past the fiddly installation (or handed the job to someone else, like me), it's a breeze to use every day.

Whether the price tag is worth it or not will ultimately boil down to your budget. If you have the cash to spend on upgrading your tap, then yes, I would highly recommend it. But if it's going to stretch you uncomfortably, then the countertop model mentioned previously could be a good alternative, costing around £200.

Unsure whether this filter is right for you? Our assistant editor Sarah Harley has also reviewed the Tappwater EcoPro Compact Tap Filter.