RESMO RS3800 Reverse Osmosis System Review: Who It Fits and Who Should Skip It
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This resmo rs3800 reverse osmosis system review focuses on a tankless under-sink unit designed for high-volume households. It delivers 800 gallons per day with a 0.55 gal/min flow rate, filling a glass in five seconds. The system uses an 8-stage filtration process with a 0.0001-micron RO membrane. It also features a 2:1 pure-to-drain ratio, which reduces wastewater significantly compared to traditional units. These specs define its performance and efficiency for daily use.
What stands out
- 800 GPD capacity with 0.55 gal/min flow rate
- 8-stage filtration using a 0.0001-micron RO membrane
- 2:1 pure-to-drain ratio saves water and reduces filter costs
- Dual water outlet with LED quality monitoring and filter life indicator
- NSF/ANSI 372 certified for lead-free materials
Who it fits
Good fit for
This system suits large families who need fast, continuous water without waiting for a tank to refill. The high 800 GPD capacity and rapid flow rate make it ideal for cooking and washing vegetables. The 2:1 wastewater ratio appeals to users prioritizing efficiency. It also fits those who want real-time water quality feedback via the LED display and filter life alerts, ensuring consistent purity without guesswork.
Who should skip it
You should look elsewhere if your sink cabinet lacks an electrical outlet or a drain pipe, as this unit requires both for operation. The dual-outlet design and LED features may be unnecessary if you only need basic drinking water. Additionally, the system requires a 1-1.4 inch hole for the faucet, which might not fit all countertop setups. Users preferring simple, non-electric filtration might find the complexity and installation requirements excessive for their needs.
Verdict: The RESMO RS3800 offers high-speed, efficient filtration for busy homes. Its tankless design and smart features make it a practical choice for those needing volume and visibility.
Key specs explained for RESMO RS3800
Capacity: 800 GPD
This rating indicates the system produces 800 gallons of purified water daily. It supports high-volume households with multiple taps or heavy usage. You will not wait long for full pitchers or large pots. Compare this to standard 50 GPD units that require storage tanks. The high output suits busy kitchens where demand exceeds small system limits.
Filtration Stages: 8
The system uses eight distinct layers to clean water before it reaches your faucet. This multi-step process targets various contaminants, including chlorine and heavy metals. More stages often mean broader protection against different impurities. You get comprehensive filtration in one unit. Check if competing systems use fewer stages for similar price points.
Pure to Drain Ratio: 2:1
For every two cups of clean water, this system wastes one cup. This ratio is efficient for modern tankless designs. It reduces water bills and environmental impact compared to older 3:1 or 4:1 models. You save water while maintaining consistent pressure. Look for this spec when comparing eco-friendly options for your home.
Design: Tankless
This unit operates without a large storage tank, saving under-sink cabinet space. It produces water on demand, ensuring freshness without stale stored water. The compact footprint fits smaller kitchens better than tank-based systems. You avoid the bulk of a pressure vessel. Compare dimensions with traditional models to verify fit in your available space.
Certification: NSF/ANSI 372
This certification confirms the materials used are lead-free and safe for drinking water contact. It verifies the physical construction meets strict health standards. You can trust the hardware does not leach harmful substances. This is a baseline safety check for any RO system. Ensure your chosen model holds this specific safety certification for peace of mind.
Design and Build Details
The unit is a tankless design intended for under-sink installation. According to the listing, the housing measures 17.1 inches in length, 15 inches in height, and 5.6 inches in width. This compact footprint allows it to fit into standard cabinetry without occupying excessive storage space for bottles or containers. The absence of a storage tank means you get water directly from the membrane, which saves room but requires consistent pressure and flow.
The system features a dual water outlet design. This layout provides separate streams for drinking and general use, allowing you to direct purified water to one tap and filtered water to another. The control interface includes an LED indicator that displays real-time water quality. This visual feedback helps you monitor the purity of the output instantly. A separate filter life indicator alerts you when maintenance is due, ensuring you replace components before performance drops.
Construction materials are certified to NSF/ANSI 372 for lead-free safety. The unit also holds FCC certification. These standards apply to the materials in contact with water and the electronic components. The faucet requires a 1 to 1.4 inch hole for installation. You will need an electrical outlet and a drain pipe nearby. The system performs an automatic 30-minute flush after installation or filter changes to prepare the membrane.
Setup and everyday use guide
Installation requires specific infrastructure. You need a 1 to 1.4 inch hole for the faucet. The unit must connect to an electrical outlet and a drain pipe. These connections support the system’s tankless design and wastewater management. After you complete the physical setup, the purifier runs an automatic 30-minute flush. It also flushes automatically after every filter change. This step is necessary to prepare the membranes for use.
Daily operation relies on real-time monitoring. The dual water outlet design includes an LED indicator that shows water quality instantly. You can see if the output meets your standards before drinking. A separate filter life indicator alerts you when replacements are needed. This helps maintain consistent purity without guesswork.
Flow performance is immediate. The 800 GPD capacity delivers 0.55 gallons per minute. You can fill an eight-ounce glass in five seconds. This speed suits families who need water for drinking or washing vegetables quickly. The system maintains a 2:1 pure to drain ratio. It produces one cup of wastewater for every two cups of pure water. This efficiency saves water compared to older tank models. The unit reduces contaminants like PFAS, chlorine, and TDS through its eight-stage process. You get clean water on demand, with no storage tank to clean or sanitize.
Check Infrastructure Before Buying
Before you finalize this purchase, verify your sink infrastructure matches the listing requirements. You must have a 1 to 1.4 inch hole for the faucet. An electrical outlet and a drain pipe are mandatory for operation. The unit includes an LED indicator for water quality and filter life, which simplifies monitoring. However, you will need to replace filters periodically. The system saves water with a 2:1 pure-to-drain ratio, but you should check if your local water pressure supports the 800 GPD capacity. If your household uses more than 800 gallons daily, this unit may struggle during peak times. Compare this high-flow tankless model against lower-capacity units if space is tight. Ensure your cabinet depth accommodates the 17.1-inch length. Proper installation prevents leaks and ensures the automatic flush cycles function correctly. Review the NSF certification for lead-free materials if safety is your priority. This system suits families needing fast, continuous purified water without storage tanks.
Check before you buy
- Verify sink hole size is 1 to 1.4 inches.
- Confirm electrical outlet and drain pipe are accessible.
- Check cabinet depth fits the 17.1-inch unit length.
- Ensure water pressure supports 800 GPD daily output.
The product at a glance
RESMO RS3800 800 GPD Tankless RO
Best for: High-flow tankless filtration with quality monitoring
- 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 an under-sink, tankless reverse osmosis system with 800 gallons per day capacity. It uses an 8-stage filtration process with a 0.0001-micron membrane to reduce contaminants like PFAS and lead. The unit features a 2:1 pure-to-drain ratio and a real-time LED water quality monitor. It requires a 1-1.4 inch hole and an electrical outlet for installation.
Pros
- 800 GPD capacity with 0.55 gal/min flow rate
- 2:1 pure-to-drain wastewater ratio
- NSF/ANSI 372 and FCC certified
- Real-time LED water quality indicator
Cons
- Requires an electrical outlet for operation
- Needs a drain pipe for wastewater disposal
- Large footprint at 17.1 inches long
Good fit if
- You need high daily water volume
- You want real-time quality monitoring
- You have space under the sink
Skip if
- You lack an electrical outlet nearby
- You cannot drill a 1.4 inch hole
- You prefer a compact tank system
Verdict: Resmo RS3800 800 GPD Tankless RO suits households needing fast, filtered water with quality feedback. It fits kitchens with power access and space for a larger unit.
Specifications side by side
| Spec | RESMO RS3800 800 GPD Tankless RO |
|---|---|
| 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 |
| Installation Type | Under sink |
| Micron Rating | 0.0001 |
| Capacity | 800 GPD |
| Dimensions | 17.1 × 5.6 × 15 inches |
| Size | 800GPD-LED 2 Way |
| Color | 800GPD-LED 2 Way |
| Model | RS3800 |
Frequently asked questions
Is the Resmo RS3800 tankless or does it use a storage tank?
This system uses a tankless design. It produces water on demand rather than storing it in a separate container. This approach saves under-sink space and prevents water from sitting stagnant. You get fresh filtered water directly from the faucet whenever you need it.
How many filtration stages does the RESMO RS3800 have?
The RESMO RS3800 features an 8-stage filtration process. This multi-stage setup ensures thorough purification of your drinking water. It targets various contaminants to deliver clean, safe water for your household. The additional stages help maintain water quality and taste effectively.
Does the Resmo RS3800 require an electrical outlet to operate?
Yes, this tankless system requires a standard electrical outlet. The internal pump needs power to push water through the membranes efficiently. You must have an available power source under your sink for installation. Without electricity, the unit cannot function or produce filtered water.
What is the pure to drain water ratio for this unit?
The RESMO RS3800 has a 2:1 pure to drain ratio. For every two gallons of clean water produced, one gallon is sent to the drain. This efficiency helps manage water waste while maintaining strong flow rates. It balances performance with responsible water usage during operation.
Is the Resmo RS3800 NSF certified?
Yes, the system is NSF certified. This certification confirms that the product meets specific public health and safety standards. You can trust that the materials and filtration process have been tested for quality. It provides assurance regarding the safety of the water it produces.
How large is the Resmo RS3800 under sink unit?
The unit measures 17.1 inches in length, 15 inches in height, and 5.6 inches in width. These dimensions allow it to fit into standard under-sink cabinets. The compact footprint helps maximize available storage space in your kitchen. It is designed to be unobtrusive while providing high-capacity filtration.