Waterdrop Under-Sink Water Filter System Comparison: Single-Stage vs. 3-Stage

In recent years, scandals regarding water safety emerge one after another and turn water filtration products to be the “must-haves” for U.S. households. Among all types of water filtration products on the market, the under-sink water filter system has been a popular option for its excellent filtration performance and little amount of maintenance effort.

In this article, I will be reviewing two best selling under-sink water filter systems from Waterdrop: the single-stage filtration system vs. the 3-stage filtration system.

Like the name suggests, this under sink filtration system has only one filter. The filter is a composite one with three kinds of filtration media to effectively reduce chlorine, odor, sediment, and other heavy metals.

This under sink filtration is built out of premium lead-free materials that are fully certified by the WQA against NSF 372 standard. The effective chlorine reduction is also certified against NSF 42 standard by the WQA.

The installation is very simple that can be completed within three minutes. Expect from the fixture on the wall under your kitchen sink, the system requires no more installation. Besides the easy installation, the system takes the minimum under sink space thus provides more room for storage.

In terms of the filter service life and maintenance cost, the system comes in three sizes featuring a lifespan of 8,000, 16,000, 19,000 gallons or 12, 24, 36 months. The extended filter life reduces the replacement frequency, so you would save much efforts and money.

The 3-stage under sink water filter system is an upgrade of the single-stage under sink system. The system has three separated filters: PP, GC and CT. These three filters represent three filtration stages using three different types of filtration media.

The PP filter uses PP cotton to filter out large particles like sand, rust and other impurities in water. The GC filter uses activated carbon granule to remove finer particles like Chlorine, bad taste and odor. The CT filter uses natural carbon block and KDF to prevent pollutants from accumulating and improve water taste furthermore.

Similar to the single-stage system, the 3-stage under sink system also takes less than 3mins to install with the easy “push-to-connect” fittings. The replacement takes only 3s with the twist-lock design.

The three filters have a lifespan of 6 months, 8-12 months, and 12-18 months, respectively.

The easy installation and minimum under sink space make the under sink water filter one of the best water solutions for people who live in a rented apartment.

Unlike many traditional reverse osmosis systems that require complex plumbing work, both the single-stage water filter and the 3-stage water filter can be connected directly to the kitchen faucet without drilling a faucet hole for the filtered water.

The only downside of the single-stage system is that you have to drill and fix the system onto the under sink wall, though it is not much of the work, many renters might still need to get permission from the landlord first.

For the 3-stage system, the problem could be solved if you place the system onto the plastic holder that comes with the package. The plastic holder would keep the system stable during working hours and you only need to take it off when replacing the filters.

The marketing data also suggests the under sink water filter as one of the most cost-effective water filtration systems for both renters and landlords.

In terms of filtration performance, the 3-stage under sink filtration system does perform better than the single-stage one, as the 3-stage adopts a larger filtration surface and more filtration media. From the maintenance perspective, the single-stage system would be more cost-effective as the replacement frequency and cost are minimal.