Want cool, filtered water on demand? This smart kitchen upgrade could be worth considering

If you love crisp, purified water but hate the look of bulky, refillable fountains, a built-in fridge filter could be the answer you're looking for.

When it comes to investing in the best filter, reverse osmosis (RO) systems are considered the gold standard. They remove impurities by forcing water through a semi-permeable membrane, offering broader filtration than activated carbon filters (which are the most common).

After coming across the Waterdrop G3P800 Alkaline RO System (available from Waterdrop), we decided to put it to the test to see whether it could deliver that chilled, silky taste – and, more importantly, reduce water hardness and remove unwanted impurities.

Waterdrop G3P800 Alkaline RO System: Specs

Waterdrop G3P800 Alkaline RO System: setting it up

This filter may look a little overwhelming when it arrives at your door, but according to our tester, Philip, it was "simpler than expected to install", and he managed to fit it to his fridge on a DIY basis.

The box includes:

• The G3P800 unit
• Pre-sediment and carbon block filter
• Activated carbon filter
• Reverse osmosis membrane filter
• Smart digital RO faucet
• UV steriliser
• Power adapter
• Feed water adapter
• Drain saddle
• White 3/8" PE tubing
• White 1/4" PE tubing
• Red 1/4" PE tubing
• Lock clips
• Teflon tape
• User manual

While the water filter is designed to be used as a tap, similar to the Waterdrop X16 RO System we previously tested, Philip attempted to install it to his fridge instead – and was surprised at just how easy it was.

"First, we removed the filter that came with the fridge. Then, we connected the grey 6mm pipe to the 10mm blue pipe using a connector that we bought from Amazon," he explains. "The grey pipe runs behind the utility sink unit, through the wall and into the back of the fridge."

He initially attached the Waterdrop tap to the filter system to flush it through before eventually connecting it to the fridge.

Waterdrop G3P800 Alkaline RO System: using the filter

Build:

Whether you decide to use the filter as a tap or connect it to your fridge, its under-sink design is discreet and out of sight – unlike other countertop options I've seen, which look bulky and unattractive.

It's worth bearing in mind that the unit measures 46 x 14.4 x 45cm and needs sufficient clearance, so you'll need to ensure you have enough space in your under-sink cabinet – or move things out, as Philip did.

Flow rate and filtration:

With a flow rate of 800GPD (gallons per day), the system can fill a 6oz cup in just five seconds. It also boasts an impressive 10-stage filtration system designed to reduce a range of substances, including:

• Fluoride
• PFOA (perfluorooctanoic acid)
• PFOS (perfluorooctanesulfonic acid)
• TDS
• Chlomium
• Chlorine
• Lead
• Heavy Metals
• Rust
• Sand
• Salt
• Nematodes
• Sediments
• VOCs (volatile organic compounds)

The filter also remineralises the water with calcium and magnesium, which as well as being good for our health, can also be a bonus for those who have sensitive indoor plants that require chlorine-free water, saving you from having to stock up on specialised water each month.

Not only does it remove a broad amount of impurities from the water, but it can also help to soften it, too, which is ideal if you live in a hard water area and have to deal with limescale clogging up your kettle.

Taste and noise levels:

When it comes to the taste of his new filtered water, Philip says it's "different" and "better" than regular tap water, and it has a slight minerally flavour.

As for the noise levels, Philip says, "The water makes a pumping sound as it comes out of the fridge but I think that it is the fridge making the noise, not the filter."

Costs:

Before you go out and splash the cash on this top-end RO system, you'll need to keep in mind that there are a few ongoing costs to replace the filters, which add up to around £162.99 per year.

Here's a full breakdown and where you can buy them:

1. CF Filter (available from Waterdrop): Every six months or after filtering 550 gallons, whichever comes first.
2. CB Filter (available from Waterdrop): Annually or after filtering 1,100 gallons, whichever comes first.
3. RO Filter (available from Waterdrop): Every two years or after filtering 2,900 gallons, whichever comes first.

Waterdrop G3P800 Alkaline RO System: test results

To find out whether the water filter lived up to its claims, our reviewer put it to the test using these pH strips from Amazon, comparing the results with his regular tap water.

While we would need to send samples to a laboratory to establish whether it effectively removes microplastics, PFAS and other heavy metals, these strips gave us a bit of insight into how well it improved water softness and other measures, such as alkalinity.

As you can see from the results below, the biggest difference the filter made was a reduction in water hardness, while many of the other readings remained largely unchanged.

Waterdrop G3P800 Alkaline RO System: final verdict

If you're serious about improving the taste, quality and softness of your water – and have the money to spare – then the Waterdrop G3P800 Alkaline RO System is absolutely worth the investment.

While installation is obviously going to be trickier than with a countertop unit, and you may have to drill into your worktop if you decide to use it as a tap, it's relatively simple for a built-in system. In our opinion, the premium price tag is completely worth it when you're using it every day.

If the Waterdrop G3P800 isn't quite right for you, our assistant editor Sarah Harley has also tested the Tappwater EcoPro Compact Water Filter for improving taste and water softness.