Waterdrop AS13 Under Sink Water Filter: features, specs and who it suits

The Waterdrop AS13 (model WD-AS13) is an under-sink water filter that connects to your cold water line and delivers filtered water to a tap. Waterdrop designs it so that it installs without drilling, which matters to renters and to anyone who doesn't want to cut into a countertop or cabinet.

Installation without drilling

The system uses a plug-and-twist design. Waterdrop says this avoids drilling and many of the compatibility worries that come with under-sink systems. In general, under-sink filters still need a connection to the cold water supply and a way to deliver the water, so read the manual's installation steps and check the fittings against your plumbing. If you aren't comfortable working with plumbing, a qualified plumber can do it, and local plumbing codes apply.

Certifications explained

The listing states two NSF/ANSI certifications:

• NSF/ANSI 42, for the reduction of chlorine, taste and odour.
• NSF/ANSI 372, for lead-free materials in the system.

The listing also says the system can reduce PFAS and PFOA/PFOS. For certification details and exact performance data, check Waterdrop's published test documentation. Performance depends on the water source and on keeping the filters in date.

Five-plus-one stages

Waterdrop describes the filtration as 5+1 stages, sold as a six-stage system. Multi-stage filters generally combine a sediment stage, carbon stages and other media, so that each layer handles something different. Waterdrop notes that the system does not lower the TDS (total dissolved solids) reading, because it adds minerals to the water. If you expect a lower TDS number, as you'd see from reverse osmosis, this isn't that kind of system.

Stainless steel build

The housing is food-grade stainless steel, which Waterdrop describes as rust-resistant, durable and leak-proof. Metal housings are generally sturdier than plastic ones and don't let light in. The unit measures about 7.3 x 6.3 x 15.4 inches and weighs 5 lb, so it fits in most sink cabinets, though a garbage disposal or pipework can take up space.

Filter life

Waterdrop gives a 12-month filter lifespan. Actual life depends on how much water you use and on your supply, so watch the flow and follow the replacement guidance in the manual.

Who it suits

It suits renters, apartment dwellers and anyone who wants filtered water at the tap without altering the kitchen. It also suits households that want a longer interval between filter changes.

What to check before you buy

• Cabinet space: measure the height, width and depth available under your sink.
• Plumbing: confirm your water line fittings and the tap or faucet you'll use.
• Water type: check what is in your supply, and whether this filter's certifications cover it.
• Replacement filters: find out how to order them and when to change them.
• Water pressure: check the manual's required range.
• Installation: follow the manual and local plumbing rules.

The short version

• An under-sink filter with a plug-and-twist, no-drilling installation.
• NSF/ANSI 42 for chlorine, taste and odour, and NSF/ANSI 372 for lead-free materials.
• Described as 5+1 stages, with a food-grade stainless steel housing.
• Does not lower TDS, because it adds minerals.
• A 12-month filter life, as rated by Waterdrop.

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