This comparison covers the top reverse osmosis systems for 2026, examining under-sink and tankless models from Waterdrop. We evaluate the G5P700A, X8 Tankless, and X12 Premium systems based on GPD output, waste ratios, remineralization features, and installation requirements to help you choose the right RO system for your home.
As an Amazon Associate I earn from qualifying purchases at no cost to you – it keeps the site running.
Overview: The Waterdrop G5P700A is an 8-stage tankless reverse osmosis system that produces 700 gallons per day while adding alkaline minerals back into filtered water. This NSF/ANSI 58 & 372 certified system features a 2:1 pure to drain ratio and comes with a smart LED faucet for monitoring filter status.
The G5P700A strikes an excellent balance between performance and efficiency, offering substantial daily output without the space requirements of traditional tank systems. Its 8-stage filtration process combines precise 0.0001 micron RO membrane technology with alkaline mineralization, adding essential minerals like calcium, magnesium, sodium, and potassium back into the purified water. The 2:1 waste ratio is more water-efficient than many competitors, and the tankless design frees up 70% of under-sink space compared to tank-based systems.
While the 700 GPD output handles most household needs effectively, families with very high water consumption might find the flow rate limiting during peak usage periods. The system's compact footprint makes installation straightforward, though the alkaline remineralization feature requires periodic filter replacements that cost more than standard RO filters. Compared to the higher-capacity X8 Tankless and X12 Premium models, this system offers the most balanced approach for typical household water needs.
Pros
700 GPD output with efficient 2:1 waste ratio
8-stage filtration with alkaline mineral addition
Tankless design saves 70% of under-sink space
NSF/ANSI 58 & 372 certified for safety
Smart LED faucet indicates filter status
Cons
Lower GPD output than premium models
Alkaline filter replacements cost more than standard filters
May struggle with very high simultaneous demand
Best for Most households seeking reliable RO filtration with mineral enhancement and space-saving design.
Overview: The Waterdrop X8 is a 10-stage tankless reverse osmosis system delivering 800 gallons per day with alkaline mineralization technology. NSF/ANSI 42, 58 & 372 certified, it maintains a 2:1 pure to drain ratio while providing rapid flow for larger households.
The X8 represents the sweet spot for tankless RO technology, delivering 100 more gallons per day than the G5P700A while maintaining the same efficient 2:1 waste ratio. Its 10-stage filtration system includes two additional processing stages compared to the G5P700A, featuring a 16-layer RO membrane that provides enhanced contaminant reduction. The system excels at handling multiple simultaneous water draws, making it ideal for busy kitchens where cooking, drinking, and cleaning happen concurrently.
The increased complexity of the 10-stage system means more filter components to maintain and replace over time, which can increase long-term operating costs. Installation requires slightly more under-sink space than the G5P700A due to additional filter housings, though it remains significantly more compact than traditional tank systems. While the 800 GPD capacity handles most household demands well, it falls short of the X12 Premium's 1200 GPD output for households with exceptionally high water usage.
Pros
800 GPD high-speed output for busy households
10-stage filtration with 16-layer RO membrane
Maintains efficient 2:1 pure to drain ratio
Triple NSF/ANSI certification (42, 58, 372)
Handles multiple simultaneous water draws effectively
Cons
More filter components increase maintenance complexity
Higher operating costs than simpler systems
Best for Active households needing higher daily water output with reliable tankless performance and mineral enhancement.
Overview: The Waterdrop X12 is a premium 11-stage tankless reverse osmosis system producing 1200 gallons per day with alkaline mineral enhancement. It features an improved 3:1 pure to drain ratio and comes with a smart stainless steel faucet for high-end installations.
The X12 represents the pinnacle of residential RO technology, delivering 1200 GPD output that can handle even the most demanding household water needs. Its 11-stage filtration system adds an extra processing stage beyond the X8 Tankless, while the improved 3:1 pure to drain ratio makes it the most water-efficient option in this comparison. The system includes enhanced LED monitoring and a premium stainless steel faucet that complements upscale kitchen designs, making it suitable for luxury installations where performance and aesthetics matter equally.
The premium positioning comes with correspondingly higher upfront costs and more complex maintenance requirements due to the extensive filtration stages. The 1200 GPD capacity, while impressive, may be overkill for smaller households and could lead to unnecessary filter cycling in low-usage scenarios. Installation requires the most under-sink space of the three systems, and the 11-stage design means more potential points of maintenance compared to the simpler G5P700A or X8 Tankless systems.
Pros
1200 GPD maximum output for high-demand households
11-stage filtration with enhanced contaminant reduction
Most efficient 3:1 pure to drain ratio
Premium stainless steel smart faucet included
NSF/ANSI triple certification with SGS testing
Cons
Highest upfront and maintenance costs
Most complex installation and maintenance requirements
Overkill capacity for smaller households
Best for Large households or luxury installations requiring maximum RO capacity with premium aesthetics and top-tier filtration performance.
Overview: The FRIZZLIFE M800 is a non-electric tankless reverse osmosis system that produces up to 900 GPD using only water pressure. This 8-stage system includes remineralization to add calcium, magnesium, and zinc back into filtered water, operating with a 4:1 pure-to-waste ratio without requiring electricity or producing noise.
The M800 stands out as the only truly cordless RO system in this comparison, eliminating the need for electrical connections that both the NU Aqua and Waterdrop WD-A1 require. Its 900 GPD capacity exceeds the NU Aqua's 600 GPD output, while the 4:1 waste ratio is less efficient than NU Aqua's 2:1 ratio but still reasonable for a non-electric system. The built-in remineralization stage sets it apart from basic RO systems by restoring essential minerals.
Installation requires sufficient under-sink space at 14.5"L x 5.1"W x 19.7"H, and the system relies entirely on incoming water pressure, which means performance can vary with your home's water pressure. Unlike electric systems, you won't get consistent flow rates during low-pressure periods, and the lack of a booster pump means slower filling compared to electric tankless systems.
Pros
No electricity required – completely cordless operation
High 900 GPD capacity without power consumption
Built-in remineralization adds essential minerals back
Silent operation with no pumps or motors
Auto-flush feature helps maintain membrane life
Cons
Performance depends on incoming water pressure
4:1 waste ratio less efficient than electric alternatives
Requires significant under-sink space
Best for Homeowners seeking a high-capacity RO system without electrical requirements or noise concerns.
Overview: The NU Aqua is a 7-stage electric tankless RO system producing 600 GPD with an efficient 2:1 pure-to-waste ratio. It features a smart LED countertop faucet that changes colors to indicate filter replacement needs, making maintenance tracking simple for busy families.
This system offers the most efficient waste ratio in our comparison at 2:1, significantly better than the FRIZZLIFE M800's 4:1 ratio, making it more water-conscious for daily family use. The 600 GPD capacity, while lower than the M800's 900 GPD, still provides ample flow for most households. The smart LED faucet provides visual maintenance reminders that neither the M800 nor Waterdrop WD-A1 offer for under-sink systems.
The electric operation ensures consistent performance regardless of water pressure fluctuations, unlike the pressure-dependent M800. However, the system requires electrical connection under the sink, which may complicate installation in some homes. The 7-stage filtration lacks the remineralization found in the M800, producing pure but mineral-free water that some users may find too "flat" tasting.
Pros
Highly efficient 2:1 pure-to-waste ratio
Smart LED faucet indicates filter replacement timing
Consistent 600 GPD performance with electric boost
7-stage filtration removes 99% of contaminants
Reliable flow rate independent of water pressure
Cons
Requires electrical connection under sink
No remineralization – produces mineral-free water
Lower 600 GPD capacity compared to M800
Best for Families wanting efficient water usage with smart maintenance tracking and consistent performance.
Overview: The Waterdrop WD-A1 is a countertop reverse osmosis system with hot and cold water dispensing capabilities, offering 6 temperature options from 41°F to 203°F and 5 volume settings. This 7-stage NSF-certified system provides instant access to filtered water without under-sink installation.
Unlike the under-sink FRIZZLIFE M800 and NU Aqua systems, the WD-A1 sits on your countertop and requires no plumbing modifications, making it ideal for renters or those wanting portable filtration. The hot/cold dispensing feature with precise temperature control from 41°F to 203°F offers convenience that neither under-sink system provides. However, this countertop design takes up valuable counter space that the hidden under-sink systems avoid.
The system's 7-stage filtration matches the NU Aqua's contaminant removal capabilities, but the countertop format limits daily capacity compared to the high-GPD under-sink systems. The built-in reservoir and heating/cooling systems require more frequent maintenance than simple under-sink RO systems, and the unit's size may not suit smaller kitchens or minimalist setups.
Pros
No plumbing installation required – completely portable
Hot and cold water dispensing with 6 temperature options
NSF/ANSI 58 & 372 certified for contaminant removal
5 volume settings for different serving sizes
Ideal for renters or temporary installations
Cons
Takes up significant counter space
Limited daily capacity compared to under-sink systems
More complex maintenance with heating/cooling components
Best for Renters or homeowners wanting instant hot/cold filtered water without permanent installation.
