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If you are researching nu aqua 6 stage UV under sink reverse osmosis system alternatives, you likely need a reliable under-sink unit with UV protection. The original NU Aqua model delivers 100 GPD output and includes a booster pump for higher flow. It also features a six-stage filtration process with ultraviolet light to kill bacteria. This combination works well for households that prioritize volume and biological safety over mineral remineralization.
However, you might prefer a different footprint, faucet finish, or filtration approach. Some buyers need a countertop unit for rental flexibility, while others want a chrome or brushed nickel faucet. Others may seek a system with a better water efficiency ratio or additional alkaline stages. We selected these 6 alternatives because their core specifications overlap with the NU Aqua system. Each option shares the 100 GPD capacity or similar under-sink installation requirements, ensuring you can compare practical specs side by side.
01 How alternatives compare to NU Aqua
NU Aqua 100 GPD UV Under Sink RO
The second NU Aqua option keeps the same 100 GPD capacity and 6-stage filtration as the original. It also includes UV protection. The main difference is the absence of a booster pump. This model relies on standard water pressure for flow. It is slightly shorter at 18 inches high compared to the 19.5-inch original. The weight is listed at 28 pounds. You get the same white finish and under-sink design. Choose this if you want a simpler setup without a pump. It suits homes with adequate water pressure. You save on complexity but lose the extra flow boost. The footprint remains compact for under-sink storage. It is a direct, streamlined version of the top pick.
iSpring RCC1UP 100 GPD Under Sink RO
The iSpring RCC1UP matches the 100 GPD output and 6-stage filtration of the NU Aqua original. It also includes a booster pump and UV filter. The key difference is its wider body. It measures 8 inches wide, while the NU Aqua is 5.5 inches wide. The height is similar at 18 inches. This unit weighs 35 pounds, making it heavier than the original. You get a robust build for high-volume drinking water. The UV filter provides germ protection. Choose this if you need a wider unit for better stability. It fits under sinks with more lateral space. You trade a narrower profile for a potentially more stable base. The performance specs align closely with the original NU Aqua model.
Express Water ROUV10D 100 GPD UV System
The Express Water ROUV10D offers 100 GPD output with 6-stage filtration and UV protection. It lacks a booster pump in its listed features. The standout feature is the chrome faucet finish. The original NU Aqua uses a stainless steel faucet. This unit is narrower at 5 inches wide. It is also lighter at 30 pounds. The height is 17 inches, making it shorter than the original. You get a modern look with the chrome finish. Choose this if aesthetic appeal matters more than flow boost. It fits standard under-sink spaces well. You sacrifice the booster pump for a sleeker design. The UV filter still provides biological protection. It is a solid choice for style-conscious buyers.
iSpring PH100 100 GPD Alkaline RO
The iSpring PH100 provides 100 GPD output with 6-stage filtration. It differs significantly by including alkaline remineralization. The original NU Aqua focuses on purification without adding minerals. This iSpring model boasts a 1:1 pure to drain ratio. This improves water efficiency compared to standard RO systems. It does not list a UV filter or booster pump. The unit is wider at 16 inches. It is taller at 19 inches. You get improved taste through remineralization. Choose this if you prefer alkaline water. You lose the UV germ protection of the original. The wider footprint requires more under-sink space. It is best for those prioritizing taste and efficiency over biological filtration.
Purevua PR1-A Countertop RO with UV
The Purevua PR1-A is a countertop unit, unlike the under-sink NU Aqua original. It offers 6-stage filtration with a UV filter. It does not list a specific GPD capacity. The unit weighs 16.5 pounds. It has a cycle capacity of 68 fl.oz. You get portability and no plumbing installation. This suits renters or those without under-sink access. The dimensions are 17.1 inches long. You trade high-volume under-sink convenience for flexibility. You do not get the 100 GPD output of the original. It is a compact solution for limited spaces. Choose this if you need a tool-free setup. The UV filter still provides biological protection. It is a practical alternative for mobile living situations.
Express Water 11-Stage Alkaline UV RO System
The Express Water 11-Stage RO UV System offers extensive filtration with 11 stages. It matches the 100 GPD capacity of the original. It includes both UV filter and alkaline remineralization. The original NU Aqua has only 6 stages. This unit features a brushed nickel faucet. The original uses stainless steel. The width is 5 inches, similar to the original. The height is 17 inches. You get comprehensive treatment for biological safety and mineral balance. Choose this if you want maximum filtration stages. You gain alkaline benefits but add complexity. The brushed nickel finish offers a different aesthetic. It is a robust choice for thorough water treatment. The 11-stage process covers more contaminants than the 6-stage original.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | NU Aqua 6-Stage UV RO System Best overall | High flow under-sink drinking water | |
| 2 | NU Aqua 100 GPD UV Under Sink RO Best budget | high-flow under-sink UV purification | |
| 3 | iSpring RCC1UP 100 GPD Under Sink RO Best premium | High-output drinking water with UV protection | |
| 4 | Express Water ROUV10D 100 GPD UV System Best chrome | chrome faucet finish and UV-C protection | |
| 5 | iSpring PH100 100 GPD Alkaline RO Best 1:1 pure to drain | water efficiency and alkaline taste | |
| 6 | Purevua PR1-A Countertop RO with UV Best countertop | renters needing portable, no-plumbing water purification | |
| 7 | Express Water 11-Stage Alkaline UV RO System Best 11-stage | comprehensive 11-stage under sink purification |
NU Aqua 6-Stage UV RO System
Best for: High flow under-sink drinking water
- Installation Type
- Under Sink
- Daily Production Rate
- 100 GPD
- Filtration Stages
- 6-Stage
- Certifications
- NSF
- Features
- UV Filter, Booster Pump
- Application
- Kitchen
This NU Aqua system uses a 6-stage filtration process with UV purification and a booster pump. It delivers a 100 GPD flow rate, which is double the output of standard under-sink filters. The unit includes a stainless steel faucet and a PPM meter. It suits you if you want high daily production and clean water from under the sink.
- 100 GPD daily production rate
- UV filtration stage for added purification
- Includes booster pump for higher pressure
- NSF certification for material safety
- Fewer filtration stages than the 11-stage Express Water option
- Does not include an alkaline remineralization stage
- Standard 3-year warranty compared to longer industry terms
- You need a high flow rate of 100 GPD
- You want UV purification in an under-sink system
- You prefer a stainless steel faucet finish
- You require an alkaline remineralization stage
- You need more than 6 filtration stages
- You prefer a countertop installation over under-sink
Verdict: NU Aqua 6-Stage UV Under Sink RO fits households needing high daily water production with UV protection. It is a solid choice for under-sink installation where flow rate matters more than remineralization.
NU Aqua 100 GPD UV Under Sink RO
Best for: high-flow under-sink UV purification
- Installation Type
- Under Sink
- Daily Production Rate
- 100 GPD
- Filtration Stages
- 6-Stage
- Certifications
- NSF
- Features
- UV Filter
- Use
- Drinking Water
The NU Aqua 6-Stage UV Under Sink Reverse Osmosis System delivers 100 GPD of filtered water. It uses a six-stage process with ultraviolet purification to remove dissolved solids. The unit includes a stainless steel faucet and a PPM meter. It fits under standard kitchen sinks. This system suits households wanting high flow rates and added UV protection for drinking water.
- 100 GPD daily production rate
- Six-stage filtration with UV purification
- Includes complimentary PPM meter
- NSF certified components
- 3-year manufacturer warranty
- Heavier at 28 pounds compared to lighter alternatives
- Standard 6-stage setup without alkaline remineralization
- Requires under-sink installation space
- You need a high-flow 100 GPD system
- You want UV sterilization for extra safety
- You prefer a stainless steel faucet
- You require countertop installation
- You want alkaline remineralization stages
- You have limited under-sink weight capacity
Verdict: NU Aqua 6-Stage UV Under Sink RO provides reliable 100 GPD output with UV protection. It fits homes needing clean, high-volume drinking water without remineralization.
iSpring RCC1UP 100 GPD Under Sink RO
Best for: High-output drinking water with UV protection
- Installation Type
- Under Sink
- Daily Production Rate
- 100 GPD
- Filtration Stages
- 6-Stage
- UV Purification
- 11W Ultraviolet UV Filter
- Features
- UV Filter, Booster Pump
- Use
- Drinking Water
This iSpring system combines a 6-stage reverse osmosis process with an 11W ultraviolet filter for drinking water. It produces 100 gallons per day and includes a booster pump to maintain flow. The unit measures 15 by 8 by 18 inches and weighs 35 pounds. You need an electrical outlet for the UV light. It fits under standard kitchen sinks and reduces over 1,000 contaminants.
- 11W ultraviolet filter kills bacteria and viruses
- 100 GPD daily production rate
- Includes booster pump for better water pressure
- Reduces up to 99% of over 1,000 contaminants
- Requires an electrical outlet for UV operation
- Weighs 35 pounds, which is bulkier than some compact units
- 6-stage filtration is fewer stages than the 11-stage option on this list
- You need a high-output system that produces 100 gallons per day
- You want ultraviolet purification to remove bacteria and viruses
- You have an electrical outlet available under your sink
- You cannot run power under your sink
- You prefer a simpler 4-stage or 5-stage setup
- You need a countertop unit that requires no installation
Verdict: iSpring RCC1UP 6-Stage UV Under Sink RO delivers strong purification with its 11W UV filter and 100 GPD output. It suits households that need high daily water volume and extra germ protection, provided you have power access.
Express Water ROUV10D 100 GPD UV System
Best for: chrome faucet finish and UV-C protection
- Installation Type
- Under-sink
- Daily Production Rate
- 100 GPD
- Filtration Stages
- 6-stage
- Features
- UV Filter
- Faucet Finish
- Chrome
- Dimensions
- 15 × 5 × 17 inches
This under-sink system uses a 6-stage reverse osmosis process paired with UV-C purification. It produces 100 gallons per day, handling typical household needs. The chrome faucet finish matches many kitchen styles. An integrated leak detector shuts off water flow if moisture is detected. You get automatic tank filling without manual activation. The unit measures 17 by 15 by 5 inches and weighs 30 pounds.
- 100 GPD daily production rate
- Chrome faucet finish
- UV-C light for biological impurities
- Emergency leak stop detector
- Heavier 30-pound build
- 6-stage filtration count
- 1-year limited warranty
- You want a chrome faucet finish
- You need under-sink UV purification
- You prefer automatic tank filling
- You need more than 100 GPD
- You want a countertop unit
- You require a longer warranty
Verdict: Express Water ROUV10D Chrome 100 GPD suits buyers who prioritize a chrome faucet and UV-C biological protection in a standard under-sink footprint.
iSpring PH100 100 GPD Alkaline RO
Best for: water efficiency and alkaline taste
- Installation Type
- Under-sink
- Daily Production Rate
- 100 GPD
- Filtration Stages
- 6-stage
- Pure to Drain Ratio
- 1:1
- Remineralization
- Alkaline remineralization
- Use
- Drinking Water
The iSpring PH100 is a 6-stage under-sink reverse osmosis system that produces 100 gallons per day. It features a 1:1 pure to drain ratio, which minimizes water waste compared to standard models. The system includes an alkaline remineralization stage to restore healthy minerals and improve taste. It uses US-made filters and a Dupont membrane. This unit fits under standard kitchen sinks and includes a brushed nickel faucet.
- 1:1 pure to drain water ratio
- 100 GPD daily production rate
- Alkaline remineralization filter stage
- US-made filters and Dupont membrane
- Brushed nickel all-metal faucet included
- 100 GPD capacity is lower than some 100 GPD+ competitors with pumps
- 6-stage filtration has fewer stages than the 11-stage alternative
- System dimensions are 16 x 17.5 x 19 inches, requiring significant under-sink space
- You want to minimize wastewater with a 1:1 ratio
- You prefer alkaline, mineral-rich drinking water
- You need a standard 100 GPD under-sink system
- You require more than 100 GPD production
- You want an 11-stage filtration system
- You prefer a countertop installation
Verdict: The iSpring PH100 Alkaline 100 GPD RO System is a practical choice for households prioritizing water efficiency and improved taste through remineralization.
Purevua PR1-A Countertop RO with UV
Best for: renters needing portable, no-plumbing water purification
- Installation Type
- Countertop
- Filtration Stages
- 6-stage
- Pure to Drain Ratio
- 3:1
- Certifications
- FCC
- UV Purification
- UV light
- Features
- UV Filter
This countertop reverse osmosis system uses a 6-stage filtration process with UV light to purify water without plumbing. It includes a high borosilicate glass pitcher and produces up to 68 fluid ounces of purified water per cycle. The unit features a 3:1 pure to drain ratio and measures 17.1 by 7 by 14.2 inches. It suits renters or those needing a portable, tool-free installation option.
- 6-stage filtration with UV light purification
- Countertop design requiring no plumbing or installation
- Produces up to 68 fl.oz (2L) of purified water per cycle
- 3:1 pure to drain water ratio
- Includes high borosilicate glass pitcher
- Weighs 16.5 pounds, making it heavier than under-sink units
- Requires 18 inches of vertical clearance for tank removal
- Produces 68 fl.oz per cycle, less than the 100 GPD capacity of other list items
- You need a water filter that requires no plumbing or professional installation
- You want a portable system for use in apartments, RVs, or offices
- You prefer a countertop unit with a glass pitcher for serving water
- You require a high-capacity system producing 100 gallons per day
- You have limited vertical clearance of less than 18 inches on your counter
- You want a permanently installed under-sink unit to save counter space
Verdict: Purevua PR1-A Countertop RO UV System is a practical choice for users who need portable, tool-free water purification. It fits renters or those without under-sink access who can accommodate its 16.5-pound weight and 68 fl.oz cycle capacity.
Express Water 11-Stage Alkaline UV RO System
Best for: comprehensive 11-stage under sink purification
- Installation Type
- Under Sink
- Daily Production Rate
- 100 GPD
- Filtration Stages
- 11-Stage
- Remineralization
- Alkaline
- UV Purification
- UV Filter
- Features
- Alkaline, UV Filter
This under sink system offers 11 filtration stages, including reverse osmosis, alkaline remineralization, and UV purification. It produces 100 gallons per day and includes a leak detection sensor for safety. The brushed nickel faucet adds a finished look. It suits you if you want comprehensive contaminant reduction and biological protection in one unit. The automatic tank filling keeps water available without manual refilling.
- 11-stage filtration reduces lead, chlorine, and fluoride
- UV filter targets biological impurities
- Alkaline stage adds calcium and potassium
- Built-in leak detection sensor shuts off water flow
- 100 GPD daily production capacity
- Larger footprint with 17-inch height and 15-inch length
- Only 1-year warranty coverage
- Limited to 100 GPD production rate
- You want UV protection alongside reverse osmosis
- You prefer alkaline remineralized water
- You need a leak detection safety feature
- You have limited under sink space
- You want a longer warranty period
- You need higher daily production capacity
Verdict: Express Water 11-Stage RO UV System provides thorough water treatment with UV and alkaline stages, making it a strong choice for households prioritizing biological safety and mineral balance.
02 Specifications side by side
| Spec | NU Aqua 6-Stage UV RO System | NU Aqua 100 GPD UV Under Sink RO | iSpring RCC1UP 100 GPD Under Sink RO | Express Water ROUV10D 100 GPD UV System | iSpring PH100 100 GPD Alkaline RO | Purevua PR1-A Countertop RO with UV | Express Water 11-Stage Alkaline UV RO System |
|---|---|---|---|---|---|---|---|
| Installation Type | Under Sink | Under Sink | Under Sink | Under-sink | Under-sink | Countertop | Under Sink |
| Daily Production Rate | 100 GPD | 100 GPD | 100 GPD | 100 GPD | 100 GPD | – | 100 GPD |
| Filtration Stages | 6-Stage | 6-Stage | 6-Stage | 6-stage | 6-stage | 6-stage | 11-Stage |
| Pure to Drain Ratio | – | – | – | – | 1:1 | 3:1 | – |
| Certifications | NSF | NSF | – | – | – | FCC | – |
| Remineralization | – | – | – | – | Alkaline remineralization | – | Alkaline |
| UV Purification | – | – | 11W Ultraviolet UV Filter | – | – | UV light | UV Filter |
| Capacity | 100 GPD | 100 GPD | 100 GPD | 100 GPD | 100 GPD | – | 100 GPD |
| Features | UV Filter, Booster Pump | UV Filter | UV Filter, Booster Pump | UV Filter | Alkaline, Remineralization | UV Filter | Alkaline, UV Filter |
| Faucet Finish | – | – | – | Chrome | – | – | Brushed Nickel |
| Use | – | Drinking Water | Drinking Water | – | Drinking Water | – | – |
| Application | Kitchen | Kitchen | – | – | – | – | – |
| Intended Use | Home | Home | – | – | – | Home | – |
| Dimensions | 15 × 5.5 × 19.5 inches | 15 × 5.5 × 18 inches | 15 × 8 × 18 inches | 15 × 5 × 17 inches | 17.5 × 16 × 19 inches | 17.1 × 6.97 × 14.2 inches | 15 × 5 × 17 inches |
| Weight | – | 28 pounds | 35 pounds | 30 pounds | – | 16.5 pounds | – |
| Size | Stage 6 UV | RO – Stage 6 UV | – | 100 Gallons/Day | – | – | – |
| Color | White | White | White | Chrome | White | – | Brushed Nickel |
| Model | WU-100GPD-WP-UV | WU-100GPD-NP-UV | RCC1UP | ROUV10D | PH100 | PR1-A | 10MBN-ROALKUV |
03 Frequently asked questions
Which NU Aqua system is best for high flow rates?
The NU Aqua 6-Stage UV Under Sink RO System (WU-100GPD-WP-UV) is the top pick for high flow. It includes a booster pump to increase water pressure and output. This model delivers 100 GPD, making it suitable for households needing consistent, high-volume drinking water without waiting for the tank to refill.
Is there a cheaper NU Aqua option without a pump?
Yes, the NU Aqua 100 GPD UV Under Sink RO (WU-100GPD-NP-UV) serves as the budget choice. It maintains the same 100 GPD capacity and 6-stage filtration but omits the booster pump. It relies on standard water pressure, which may result in slower fill times compared to the pumped version.
How does the iSpring RCC1UP compare to NU Aqua?
The iSpring RCC1UP also offers 100 GPD output and 6-stage filtration with UV protection. It includes a booster pump like the top NU Aqua pick. However, it is slightly wider at 8 inches versus 5.5 inches. It weighs 35 pounds, so ensure your cabinet has adequate space and weight support.
Can I get a chrome faucet with a UV system?
The Express Water ROUV10D Chrome 100 GPD System features a chrome faucet finish. It provides 100 GPD capacity and 6-stage filtration with UV-C biological protection. Its dimensions are compact at 5 inches wide, fitting standard under-sink spaces. This model prioritizes aesthetic appeal alongside standard purification performance.
Which system saves the most water during filtration?
The iSpring PH100 Alkaline 100 GPD RO System is best for water efficiency. It features a 1:1 pure to drain ratio, meaning it wastes less water than standard RO units. It also includes alkaline remineralization stages to improve taste. Note that it lacks UV protection, focusing instead on mineral balance and efficiency.
Is there a countertop option if I cannot install under the sink?
The Purevua PR1-A Countertop RO with UV is designed for renters or those without under-sink access. It requires no plumbing installation and sits on your counter. It features 6-stage filtration with UV protection. The unit weighs 16.5 pounds and holds a 68 fl.oz cycle capacity, offering portable purification without permanent modification.
Which system offers the most filtration stages?
The Express Water 11-Stage Alkaline UV RO System provides the most comprehensive treatment. It uses 11 stages, including UV filtration and alkaline remineralization. It delivers 100 GPD output and features a brushed nickel faucet. This model is ideal if you prioritize thorough biological safety and mineral balance over simple filtration.
