RESMO RS3800 800 GPD Tankless Alternatives: 6 Similar Picks Compared
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You are looking for resmo rs3800 800 gpd tankless alternatives because the original system may not fit every kitchen layout or filtration need. The RESMO RS3800 delivers 800 gallons per day with an 8-stage filtration process and a 2:1 pure to drain ratio. It includes NSF/ANSI 372 certification and an LED faucet for real-time water quality monitoring. These specs make it a strong choice for high-flow households. However, you might prefer a different size, a lower capacity, or a system with alkaline remineralization. Some users may also want a brand with a different design profile or a more compact footprint under the sink.
This list covers 6 similar picks that share key specifications with the RESMO RS3800. We selected these alternatives because their specs overlap with the original system. You will find options with 800 GPD capacity, tankless designs, and under-sink installation types. Other choices offer 500 GPD or 450 GPD outputs for smaller households. All listed products maintain high filtration stages and efficient water ratios. This approach ensures you can compare systems based on published data rather than subjective claims. You can choose the model that best matches your specific space and water quality requirements.
Our top pick: RESMO RS3800 800 GPD Tankless RO System.
How each alternative compares
RESMO RS3800 800 GPD Tankless RO
This listing is a variant of the RESMO RS3800, sharing the same 800 GPD capacity, 8-stage filtration, and 2:1 pure to drain ratio. It maintains the tankless design and NSF certification found in the original. The primary difference lies in the specific model configuration, identified as the LED 2 Way version. You get identical performance metrics and under-sink dimensions of 5.6 by 15 by 17.1 inches. Choose this if you specifically need the dual-outlet faucet feature for separate purified and filtered water streams. It offers the same high flow and monitoring capabilities, ensuring consistent water quality for busy households without requiring a storage tank.
Frizzlife PX500 500 GPD Tankless RO
The Frizzlife PX500 reduces daily output to 500 GPD, which is lower than the RESMO RS3800. It keeps the 8-stage filtration and tankless design but adds an alkaline filter feature. This system prioritizes remineralization over maximum volume, making it suitable for smaller households that value water pH balance. The dimensions are slightly different, measuring 5.5 by 17.7 by 14.2 inches. It shares the 2:1 pure to drain ratio and NSF certification. Pick this if you prefer alkaline water and have less space under the sink. You trade some flow speed for added mineral benefits and a more compact footprint.
Ivation H2O 800 GPD Tankless RO
The Ivation H2O matches the RESMO RS3800 with 800 GPD capacity, 8-stage filtration, and a tankless design. It also holds NSF certification and includes a smart display faucet for status monitoring. The physical size is larger, at 5.9 by 14.6 by 18.5 inches. This system fits users who want high flow and visual feedback on water quality. It offers the same efficiency and under-sink installation type. Choose this if you find a better value in the Ivation model while needing identical performance specs. It provides reliable purified water without a tank, ideal for kitchens where space allows for its slightly wider profile.
RESMO RS3800 800 GPD Tankless RO System
This RESMO RS3800 unit is another variant of the original, offering the same 800 GPD capacity, 8-stage filtration, and 2:1 pure to drain ratio. It shares the tankless design and NSF certification. The main distinction is the specific color and size configuration, listed as White-RS3800. It weighs 29.1 pounds and has the same dimensions of 5.6 by 15 by 17.1 inches. This option is for buyers who prefer this specific aesthetic or bundle configuration. You get the same real-time water quality monitoring and fast flow rates. It is a direct alternative if you want the original performance but with a different visual finish or included components.
ARLIME 800 GPD Tankless RO System
The ARLIME 800 GPD system matches the RESMO RS3800 in daily capacity, filtration stages, and tankless design. It also features a 2:1 pure to drain ratio. Like the original, it includes a smart faucet for TDS data and water quality monitoring. The dimensions are not explicitly listed, but it is designed for tight under-sink spaces. It lacks the specific NSF certification mentioned for the RESMO model in the provided data. Choose this if you prioritize high flow and smart monitoring in a compact form. It is a strong alternative for small kitchens needing high output, though you may want to verify certification details separately.
Waterdrop WD-T4-A 450 GPD Alkaline RO
The Waterdrop WD-T4-A offers 450 GPD, which is lower than the RESMO RS3800. It features 10-stage filtration, adding two more stages than the original. It includes an alkaline filter and holds NSF certification. The design is tankless with a 2:1 pure to drain ratio. Dimensions are 6.22 by 18 by 16.5 inches, making it taller than the RESMO. This system suits users who value alkaline mineralization and dual flow over high volume. Pick this if you prefer remineralized water and do not need the maximum 800 GPD output. It provides certified filtration in a slightly larger footprint, focusing on water quality enhancement rather than speed.
Quick picks
Our 7 picks
RESMO RS3800 800 GPD Tankless RO System
Best for: high-flow households wanting quality monitoring
- Filtration Stages
- 8
- Capacity (GPD)
- 800
- Design
- Tankless
- Pure to Drain Ratio
- 2:1
- Certification
- NSF/ANSI 372, FCC
- Filtration Type
- Reverse osmosis
View on Amazon: RESMO RS3800 800 GPD Tankless RO System Affiliate link
The RESMO RS3800 is a tankless under-sink reverse osmosis system with an 800 GPD capacity. It uses 8-stage filtration with a 0.0001 micron membrane to remove contaminants. The unit features a 2:1 pure-to-drain ratio and an LED faucet that displays water quality. It requires a power outlet and drain line for installation. This system suits households needing high flow rates without storage tanks.
Pros
- 800 GPD tankless design for fast flow
- 8-stage filtration with 0.0001 micron membrane
- LED faucet shows real-time water quality
- 2:1 pure to drain water ratio
- NSF/ANSI 372 lead-free certification
Cons
- Requires electrical outlet for operation
- Needs existing drain line for wastewater
- Faucet requires 1-1.4 inch pre-set hole
Good fit if
- You need high daily water volume
- You want real-time quality monitoring
- You have space for under-sink installation
Skip if
- You lack a nearby power outlet
- You cannot drill a 1.4 inch hole
- You prefer systems without wastewater drainage
Verdict: The RESMO RS3800 800 GPD Tankless RO delivers high-capacity filtration with smart monitoring for busy households. It fits users who prioritize flow speed and water quality visibility over passive filtration.
RESMO RS3800 800 GPD Tankless RO
Best for: High-flow households needing tankless efficiency
- Filtration Stages
- 8
- Capacity (GPD)
- 800
- Design
- Tankless, under sink
- Pure to Drain Ratio
- 2:1
- Certification
- NSF/ANSI 372, FCC
- Filtration Type
- Reverse osmosis
View on Amazon: RESMO RS3800 800 GPD Tankless RO Affiliate link
The RESMO RS3800 is a tankless, under-sink reverse osmosis system with an 800 GPD capacity. It uses an 8-stage filtration process with a 0.0001-micron membrane to reduce contaminants like PFAS and TDS. The unit features a 2:1 pure-to-drain ratio and includes an LED display for real-time water quality monitoring. This model suits households needing high daily output without the bulk of a storage tank.
Pros
- 800 GPD capacity with 0.55 gal/min flow rate
- 8-stage filtration reduces PFAS, TDS, and heavy metals
- 2:1 pure-to-drain ratio saves water
- LED indicator shows real-time water quality
- NSF/ANSI 372 certified for lead-free materials
Cons
- Requires an electrical outlet for operation
- Needs a drain pipe for wastewater disposal
- Faucet installation requires a 1-1.4 inch hole
Good fit if
- You need high daily water volume for cooking and drinking
- You want to avoid the space taken by a storage tank
- You prefer real-time water quality monitoring via LED
Skip if
- You do not have access to an electrical outlet under the sink
- You cannot accommodate a 1-1.4 inch faucet hole
- You lack a nearby drain pipe for wastewater
Verdict: RESMO RS3800 800 GPD Tankless RO is a high-output system for users who prioritize speed and water efficiency. It fits kitchens where power and drainage are available, delivering consistent purified water without tank storage.
Frizzlife PX500 500 GPD Tankless RO
Best for: Efficient alkaline water production
- Filtration Stages
- 8
- Capacity (GPD)
- 500 GPD
- Design
- Under sink, tankless
- Pure to Drain Ratio
- 2:1
- Certification
- NSF/ANSI 58, 53, 42, 372
- Filtration Type
- Reverse osmosis, alkaline
View on Amazon: Frizzlife PX500 500 GPD Tankless RO Affiliate link
The Frizzlife PX500 is a tankless under-sink reverse osmosis system with a 500 GPD capacity. It uses an 8-stage filtration process with a 0.0001-micron membrane to remove contaminants. An alkaline filter raises the pH above 7.5. It features a 2:1 pure-to-drain ratio. The compact design saves space. This unit suits you if you want remineralized water and efficient water usage.
Pros
- 500 GPD tankless design
- 8-stage alkaline filtration
- NSF/ANSI 58, 53, 42, 372 certified
- 2:1 pure-to-drain ratio
Cons
- Lower 500 GPD capacity than 800 GPD peers
- Flow rate limited to 0.4 GPM
- No smart connectivity mentioned
Good fit if
- You need NSF certified alkaline water
- You want a compact tankless unit
- You prioritize water efficiency
Skip if
- You require high flow rates above 0.4 GPM
- You need 800 GPD or higher capacity
- You want app-based monitoring
Verdict: Frizzlife PX500 500 GPD Alkaline RO is a certified, efficient choice for small households seeking remineralized water. It fits buyers who value space-saving tankless designs over maximum output speed.
Ivation H2O 800 GPD Tankless RO
Best for: High-flow tankless drinking water with status display
- Filtration Stages
- 8
- Capacity (GPD)
- 800
- Design
- Tankless
- Pure to Drain Ratio
- 3:1
- Certification
- NSF/ANSI 42, 58, 372
- Filtration Type
- Reverse osmosis
View on Amazon: Ivation H2O 800 GPD Tankless RO Affiliate link
The Ivation H2O is an 800 GPD tankless reverse osmosis system designed for under-sink installation. It uses an 8-stage filtration process with a 3:1 pure-to-drain ratio. The unit includes a smart LED faucet that displays water quality and filter status. With NSF/ANSI 42, 58, and 372 certifications, it targets households needing high daily output without a storage tank.
Pros
- 800 GPD tankless capacity for on-demand water
- 8-stage reverse osmosis filtration process
- NSF/ANSI 42, 58, and 372 certified
- Smart LED faucet shows TDS and filter life
- Compact design uses only two filters
Cons
- No mention of app or remote control
- Requires under-sink space for unit and plumbing
- Professional installation is recommended
Good fit if
- You want high daily flow without a tank
- You need NSF-certified contaminant reduction
- You prefer a faucet with status display
Skip if
- You need a countertop or pitcher system
- You require app-based monitoring or control
- You cannot install under the sink
Verdict: Ivation H2O 800 GPD Tankless RO suits buyers who prioritize certified filtration and a smart display faucet in a compact, tankless form factor.
RESMO RS3800 800 GPD Tankless RO System
Best for: real-time water quality monitoring
- Filtration Stages
- 8
- Capacity (GPD)
- 800
- Design
- Tankless
- Pure to Drain Ratio
- 2:1
- Certification
- NSF/ANSI 372, FCC
- Filtration Type
- Reverse osmosis
View on Amazon: RESMO RS3800 800 GPD Tankless RO System Affiliate link
The RESMO RS3800 is a tankless reverse osmosis system with an 800 GPD capacity. It uses an 8-stage filtration process with a 0.0001 micron membrane. The unit features a dual water outlet and a smart display for real-time quality monitoring. It holds NSF/ANSI 372 certification for lead-free materials. This system suits you if you need high flow rates and want to monitor water purity directly at the faucet.
Pros
- 800 GPD capacity fills an 8-ounce glass in 5 seconds
- 8-stage filtration reduces PFAS, TDS, and chlorine
- Smart display shows real-time water quality and filter life
- 2:1 pure to drain ratio saves water
Cons
- Requires an electrical outlet for the smart display and pump
- Needs a drain pipe for wastewater disposal
- Faucet requires a 1 to 1.4 inch hole for installation
Good fit if
- You need high flow rates for cooking or filling containers
- You want to see real-time TDS levels on the faucet
- You have space for a tankless unit under your sink
Skip if
- You do not have access to an electrical outlet under the sink
- You cannot drill a 1.4 inch hole for the faucet
- You prefer a system without a drain pipe connection
Verdict: The RESMO RS3800 800 GPD Tankless RO is a high-capacity system for households that value real-time water quality visibility and fast flow rates. It fits well in kitchens with power and drainage access.
ARLIME 800 GPD Tankless RO System
Best for: Small kitchens needing high flow and TDS data
- Filtration Stages
- 8
- Capacity (GPD)
- 800
- Design
- Under sink, tankless
- Pure to Drain Ratio
- 2:1
- Filtration Type
- Reverse osmosis, alkaline
- Installation Type
- Under sink
View on Amazon: ARLIME 800 GPD Tankless RO System Affiliate link
The ARLIME 800 GPD tankless system offers 8-stage filtration with a 0.0001 μm membrane. It includes an alkaline filter for mineral addition and a 2:1 pure-to-drain ratio. The compact 15-inch design saves under-sink space. A smart LED faucet displays TDS and filter life. Auto-flushing supports routine maintenance. This unit suits small kitchens needing high flow.
Pros
- 800 GPD capacity fills a 6oz cup in 5 to 7 seconds
- 8-stage filtration adds alkaline minerals for taste
- 2:1 pure-to-drain ratio reduces wastewater
- Smart LED faucet shows TDS and filter life
Cons
- Tankless design lacks a storage tank for buffer
- Smart faucet requires electrical power for LED
- No mention of bypass valve for manual override
Good fit if
- You need high flow without a large tank
- You want real-time TDS monitoring at the faucet
- You have limited under-sink cabinet space
Skip if
- You require a battery-operated faucet without wiring
- You prefer a system with a built-in storage tank
- You need a faucet without electronic components
Verdict: The ARLIME 800 GPD Tankless RO System fits homes with tight under-sink space that still require high daily output. Its smart faucet provides useful data, though the lack of a tank means flow stops if power fails.
Waterdrop WD-T4-A 450 GPD Alkaline RO
Best for: alkaline water needs and dual flow
- Filtration Stages
- 10
- Capacity (GPD)
- 450 GPD
- Design
- Under sink
- Pure to Drain Ratio
- 2:1
- Certification
- NSF/ANSI 372
- Filtration Type
- Reverse osmosis, alkaline
View on Amazon: Waterdrop WD-T4-A 450 GPD Alkaline RO Affiliate link
This tankless reverse osmosis system offers 450 gallons per day of filtered water. It features a 10-stage filtration process with an alkaline mineralizer. The unit includes dual water flow options for standard or enhanced mineral output. It holds NSF/ANSI 372 certification and maintains a 2:1 pure-to-drain ratio. You get a compact design that saves under-sink space. The system requires an electrical connection for operation.
Pros
- 10-stage filtration with alkaline mineralizer
- Dual water flow options
- NSF/ANSI 372 certified
- 2:1 pure to drain ratio
- Tankless design saves space
Cons
- 450 GPD capacity is lower than the 800 GPD competitors
- Requires countertop drilling for faucet installation
- Needs electrical connection to operate
Good fit if
- You want alkaline mineral-enhanced water
- You prefer dual flow options
- You need NSF/ANSI 372 certification
Skip if
- You require 800 GPD flow rate
- You cannot drill countertop holes
- You need a system without electrical connection
Verdict: Waterdrop WD-T4-A 450 GPD 10-Stage RO suits those prioritizing alkaline mineralization and dual flow over high volume. It fits users who value certified filtration and compact tankless design despite the lower daily capacity.
Specifications side by side
| Spec | RESMO RS3800 800 GPD Tankless RO System | RESMO RS3800 800 GPD Tankless RO | Frizzlife PX500 500 GPD Tankless RO | Ivation H2O 800 GPD Tankless RO | RESMO RS3800 800 GPD Tankless RO System | ARLIME 800 GPD Tankless RO System | Waterdrop WD-T4-A 450 GPD Alkaline RO |
|---|---|---|---|---|---|---|---|
| Filtration Stages | 8 | 8 | 8 | 8 | 8 | 8 | 10 |
| Capacity (GPD) | 800 | 800 | 500 GPD | 800 | 800 | 800 | 450 GPD |
| Design | Tankless | Tankless, under sink | Under sink, tankless | Tankless | Tankless | Under sink, tankless | Under sink |
| Pure to Drain Ratio | 2:1 | 2:1 | 2:1 | 3:1 | 2:1 | 2:1 | 2:1 |
| Certification | NSF/ANSI 372, FCC | NSF/ANSI 372, FCC | NSF/ANSI 58, 53, 42, 372 | NSF/ANSI 42, 58, 372 | NSF/ANSI 372, FCC | not stated | NSF/ANSI 372 |
| Filtration Type | Reverse osmosis | Reverse osmosis | Reverse osmosis, alkaline | Reverse osmosis | Reverse osmosis | Reverse osmosis, alkaline | Reverse osmosis, alkaline |
| Contaminants Removed | not stated | not stated | PFAS, fluoride, chlorine, lead, TDS | not stated | not stated | not stated | not stated |
| Installation Type | Under sink | Under sink | Under sink | Under sink | not stated | Under sink | Under sink |
| Features | not stated | not stated | Smart filter life reminder | not stated | not stated | Smart LED faucet, auto-flushing | not stated |
| Micron Rating | 0.0001 microns | 0.0001 | 0.0001 µm | not stated | 0.0001 | 0.0001 μm | not stated |
| Capacity | 800 GPD | 800 GPD | not stated | 800 GPD | 800 GPD | 800 GPD | not stated |
| Use | not stated | not stated | not stated | Drinking Water, Home, Kitchen | not stated | not stated | not stated |
| Dimensions | 17.1 × 5.6 × 15 inches | 17.1 × 5.6 × 15 inches | 14.2 × 5.5 × 17.7 inches | 18.5 × 5.9 × 14.6 inches | 17.1 × 5.6 × 15 inches | not stated | 16.5 × 6.22 × 18 inches |
| Weight | not stated | not stated | not stated | not stated | 29.1 pounds | not stated | 24.2 pounds |
| Model | RS3800-M | RS3800 | PX500 | IVAROWP800GPD | RS3800 | not stated | WD-RT44D-WAD |
| Size | not stated | 800GPD-LED 2 Way | not stated | 800 GPD | White-RS3800 | not stated | 450 GPD |
| Color | not stated | 800GPD-LED 2 Way | Pure White | not stated | White-RS3800 | not stated | White - Alkaline Water |
Frequently asked questions
Which tankless RO system offers the highest daily capacity?
The RESMO RS3800, Ivation H2O, and ARLIME systems all provide 800 GPD capacity. This high output suits busy households needing fast flow rates without storage tanks. The Frizzlife PX500 offers 500 GPD, while the Waterdrop WD-T4-A provides 450 GPD. Choose the 800 GPD models if speed is your priority.
Are there tankless RO options with alkaline filters?
Yes, the Frizzlife PX500 and Waterdrop WD-T4-A include alkaline filters. These systems remineralize water to improve taste and pH levels. The Frizzlife model is a 500 GPD unit, while the Waterdrop is a 450 GPD system. Both are ideal for buyers seeking enhanced mineral content in their drinking water.
Which models are NSF certified?
The RESMO RS3800, Frizzlife PX500, Ivation H2O, and Waterdrop WD-T4-A are all NSF certified. This certification verifies that the filtration stages meet specific safety and performance standards. The ARLIME system does not list certification in its attributes. NSF certification provides assurance regarding the quality of the purified water output.
Do these systems use a 2:1 pure to drain ratio?
Most listed systems use a 2:1 pure to drain ratio. This means for every two gallons of purified water produced, one gallon is sent to the drain. The RESMO RS3800, Frizzlife PX500, Waterdrop WD-T4-A, and ARLIME systems all feature this efficiency. It helps reduce water waste during the filtration process.
Which tankless RO is best for tight under-sink spaces?
The Frizzlife PX500 has a compact length of 14.2 inches, making it suitable for smaller cabinets. The RESMO RS3800 measures 17.1 inches in length. The Ivation H2O is slightly wider at 5.9 inches. Measure your available space carefully before purchasing, as tankless units still require adequate clearance for filter replacements.
Which system provides real-time water quality monitoring?
The RESMO RS3800 and ARLIME systems are noted for real-time water quality monitoring. These units often include smart faucets that display TDS data. This feature allows you to see filtration status instantly. The Ivation H2O also features a status display. This visibility helps you track filter health and water purity effectively.
Is there a 10-stage filtration option available?
The Waterdrop WD-T4-A is a 10-stage filtration system. Most other options, including the RESMO RS3800, Frizzlife PX500, and Ivation H2O, use 8-stage filtration. The extra stages in the Waterdrop model may offer additional purification layers. This is beneficial if you prioritize extensive filtration over maximum daily gallon output.