Cloud water filter is a smart under-sink reverse osmosis system launched by Cloud Water Filters in San Diego in 2023. The system removes 99% of contaminants from tap water, adds minerals back in, and tracks water quality through a smartphone app.
Cloud RO holds NSF 58 certification and achieves a 98% TDS removal rate on its performance data sheet. Lab testing confirmed 100% removal of disinfection byproducts and fluoride under household conditions. The system features a 1:1 water efficiency ratio — the best in its class — and refills its 2.8-gallon tank faster than any comparable under-sink RO system tested independently. Wirecutter, WaterFilterGuru, and Quality Water Lab all ranked Cloud RO as the top under-sink reverse osmosis system available.
Reviewers consistently praise Cloud RO’s easy installation, alkaline-tasting water, and real-time app monitoring. The system retails at $649 with a 100% money-back guarantee and HSA/FSA eligibility. This review covers performance, contaminant removal, installation, costs, and how Cloud RO compares to the Waterdrop G3P800.
What Is the Cloud Water Filter?
The Cloud water filter is a smart under-sink reverse osmosis system that removes 99% of contaminants, restores minerals, and tracks water quality via a smartphone app. Cloud Water Filters launched the product publicly in early 2023. The system targets households dealing with PFAS, fluoride, lead, and other chemicals entering homes through aging water infrastructure.
Here’s the thing — Cloud Water Filters didn’t just build another water filter. The San Diego-based company developed connected filtration technology that gives you visibility into your water quality directly from your phone. It’s a genuinely modern take on an old category.
The typical Cloud RO buyer is a health-focused household that’s done paying for bottled water delivery. The system fits under a standard kitchen sink and connects to a dedicated countertop faucet. Setup is self-contained and surprisingly simple for what it does.
What Does Cloud RO Do to Your Tap Water?
Cloud RO converts tap water into pure, alkaline drinking water by removing 99% of toxins and adding back calcium, magnesium, and potassium. The system targets fluoride, PFAS, microplastics, and heavy metals across multiple filtration stages. After purification, the remineralization stage restores trace minerals stripped by the RO membrane.
Bottom line: the remineralization filter raises water pH to a range of 8-9 on the pH scale. That makes Cloud RO water taste clean and slightly alkaline. And here’s the part most people miss — no add-on cartridge is required. Remineralization is built into the standard system from day one.
Who Makes the Cloud Water Filter?
Cloud Water Filters is a San Diego-based company that launched in 2023 and quickly earned NSF 58 certification, placement in Yahoo! Finance and mindbodygreen, and recognition as Wirecutter’s top pick for best reverse osmosis system. The company focuses exclusively on connected filtration technology for residential use.
Cloud backs every purchase with a 1-year warranty and a 100% money-back satisfaction guarantee. The system is HSA/FSA eligible. Affirm financing is available for customers who prefer monthly payments. So the barrier to entry here is lower than it looks at first glance.
How Does the Cloud Water Filter Work?
Cloud RO uses reverse osmosis technology combined with sediment, carbon, and remineralization stages to produce clean, alkaline water stored in an under-sink holding tank. Water is forced through a semipermeable membrane that blocks contaminants as small as dissolved salts and heavy metals. The process is pressure-driven and does not require a power outlet.
In fact, Cloud RO goes a step further than most systems. An internal hydraulic pump doubles the system’s water pressure — allowing connection to a refrigerator, ice maker, or basement installation without pressure loss. Traditional RO systems can’t do that. Built-in sensors track water quality and consumption over time, then send that data to the Cloud app via Bluetooth.
The 2.8-gallon (10.6L) holding tank stores purified water so it’s ready the moment the tap opens. The tank refills automatically after each use. At 80 GPD (gallons per day), Cloud refills its tank in approximately 23 minutes — faster than any comparable tank-based RO system in independent testing. Does that matter? For a family of four using water constantly throughout the day, yes, it does.
What Filtration Stages Does Cloud RO Use?
Cloud RO runs water through four stages: sediment filtration, carbon filtration, an RO membrane, and a remineralization stage that adds minerals back into purified water. Sediment filtration captures dirt, rust, and debris. Carbon filtration removes chlorine and VOCs. The RO membrane eliminates up to 99% of remaining contaminants including PFAS, lead, and fluoride.
Pre and post filters each handle 500 gallons before replacement. The RO membrane lasts up to 1,500 gallons. For a typical family of four, the full replacement cycle falls every 9-12 months at an average cost of $200-$250 per year. Cloud monitors consumption and filter health through the app and only recommends replacements when the data confirms they’re needed — not on some arbitrary timeline.
What Is the Cloud RO App?
The Cloud RO app displays real-time TDS readings, tank volume, filter lifespan, water consumption trends, and local water quality violation notifications — available for both iOS and Android devices. Users connect to the system via Bluetooth during setup, which takes only a few minutes. The app scans for the unit, connects, and begins monitoring automatically.
Here’s why this matters: filter replacement recommendations are based on actual household consumption and water toxin data — not a calendar. Replacement filters only ship when the system determines they’re needed. This means some households replace filters less frequently than the 9-12 month average depending on how much water they actually use.
What Contaminants Does Cloud Water Filter Remove?
Cloud RO is tested and claimed to remove 200-plus contaminants, including PFAS, lead, fluoride, pesticides, pharmaceuticals, chlorine, arsenic, bacteria, viruses, and dissolved salts. The system holds NSF 58 certification covering TDS reduction and has published independent NSF test data for individual contaminants including chlorine, chloramine, lead, VOCs, forever chemicals, chromium 6, nitrate, and fluoride.
In a third-party lab test performed in Denver, Colorado, Cloud RO achieved 100% removal of disinfection byproducts, fluoride, aluminum, copper, manganese, molybdenum, and strontium. Barium was reduced by 78% and sulfate by 94%. Post-filtration fluoride levels fell below the lab’s detection threshold. To be clear — that’s not a marketing claim. That’s a lab result.
Contaminants Removed by Cloud RO:
- PFAS (forever chemicals)
- Lead and heavy metals
- Fluoride (80-99% removal)
- Disinfection byproducts (100% in lab test)
- Pesticides and pharmaceuticals
- Chlorine and chloramine
- Arsenic, bacteria, and viruses
- Dissolved salts and nitrates
Does Cloud RO Remove Fluoride and PFAS?
Yes. Cloud RO removed fluoride at a rate of 80-99% in independent lab testing, with post-filtration levels falling below the lab’s detection threshold — indicating near-complete removal under real household conditions. The system also showed 100% removal of disinfection byproducts, which include chlorination byproducts linked to elevated cancer risk in high concentrations.
For PFAS (forever chemicals), NSF test data confirmed very high removal rates. Cloud RO’s multi-stage design — combining carbon and RO membrane filtration — addresses PFAS at two separate points in the process. No single-stage filter achieves the same result against PFAS. That’s an important distinction for anyone seriously concerned about forever chemicals in their tap water.
Is Cloud Water Filter NSF Certified?
Yes. Cloud RO holds NSF 58 certification, which specifically governs reverse osmosis systems and validates TDS reduction — with Cloud achieving a 98% TDS removal rate on its performance data sheet. NSF 58 is the most rigorous certification available for point-of-use RO systems. It requires third-party testing against strict reduction criteria.
NSF 58 targets the smallest particles in water — total dissolved solids. Systems certified under this standard must demonstrate consistent reduction across multiple test cycles. Cloud has also provided its own NSF test data for individual contaminants including chlorine, lead, PFAS, chromium 6, and fluoride. The removal rates across all tested substances were very high.
What Are the Benefits of the Cloud Water Filter?
Cloud RO combines 99% contaminant removal, built-in remineralization, app monitoring, battery-powered operation, and a 1:1 water efficiency ratio — a combination no single competing system fully matches. The unit measures 11 x 7 x 16 inches (27.9 x 17.8 x 40.6 cm) and fits all standard under-sink cabinets. The 2.8-gallon tank stores purified water for immediate access every time the tap opens.
Here’s what that 1:1 efficiency ratio actually means. Traditional RO systems waste 4-10 gallons of water for every 1 gallon purified. Cloud RO wastes exactly 1 gallon for every 1 gallon it produces. That 54% efficiency rating is the highest available among under-sink RO systems based on independent reviews. So you’re not just getting cleaner water — you’re getting it more sustainably.
Key Benefits at a Glance:
- 99% contaminant removal (200-plus substances)
- Built-in remineralization (no add-on cartridge needed)
- 1:1 water waste ratio (54% efficiency — best in class)
- Battery-powered — no electrical outlet required
- Real-time app monitoring via Bluetooth
- Compatible with fridge and ice maker hookups
Does Cloud RO Remineralize Water?
Yes. Cloud RO includes a built-in remineralization stage that adds calcium, magnesium, potassium, sodium, and trace minerals back into purified water — producing a TDS of 66 ppm and a pH of 8-9. Standard RO systems strip all minerals during purification, leaving water with a flat or acidic taste. Cloud solves this problem natively, without requiring an aftermarket cartridge.
Independent testers consistently note Cloud-filtered water tastes better than comparable RO outputs. The good news? The mineral content at 66 ppm TDS sits well above the near-zero readings of non-remineralizing systems. Reviewers describe the water as clean, slightly alkaline, and noticeably better-tasting than tap or standard filtered water.
How Fast Does Cloud RO Dispense Water?
Cloud RO delivers 2 liters (68 oz / half a gallon) in one minute from a full tank — equal to an 8 oz glass in approximately 7 seconds — at an 80 GPD production rate. Flow slows as the tank empties, reaching 1 minute 40 seconds per 2 liters at half-tank capacity. For typical household use — pouring a glass or filling a water bottle — these rates present no practical inconvenience.
And here’s the best part: Cloud RO refills its 2.8-gallon (10.6L) tank in approximately 23 minutes after depletion. That’s the fastest tank refill time recorded among all tank-based under-sink RO systems tested in the same independent review. A family of four can dispense 2.2 gallons (8.3L) before faucet flow noticeably slows. At 23 minutes to refill, that’s rarely a problem in practice.
What Do Cloud Water Filter Reviews Say?
Cloud RO earned top rankings from Wirecutter, WaterFilterGuru (9.24/10), and Quality Water Lab, which returned a Health score of 99 and Aesthetics score of 99 in a September 2025 lab test. Most user reviews highlight easy installation, great-tasting water, and reliable app monitoring. Expert reviewers cite lab-verified contaminant removal and best-in-class efficiency as the defining strengths.
One quality water expert who switched from the Waterdrop G3P800 in August 2025 pulled a September lab test score of 97/99 overall. The expert noted Cloud RO covers more ground than any comparable system at its price point. Multiple independent sources rank Cloud RO as the top under-sink RO system available right now. That’s a consistent signal — not an outlier review.
Expert Scores:
| Source | Score | Ranking |
|---|---|---|
| WaterFilterGuru | 9.24/10 | #1 Under-Sink RO |
| Quality Water Lab | Health 99/Aesthetics 99 | #1 Overall RO |
| Wirecutter | Top Pick | #1 Best RO System |
| Quality Water Lab Expert | 97/99 | #1 Ranked |
What Are the Positive Experiences?
Positive Cloud RO reviews consistently praise easy installation, great water taste, compact design, and the app’s real-time monitoring as the system’s defining strengths. One reviewer described the process as one of ‘the best designed with ease in mind installation processes’ ever completed. Another noted installation took approximately 30 minutes and that ‘everything is clearly labeled and organized.’
So what does that mean for you? Several users replaced bottled water delivery services after switching to Cloud RO. One replaced a $55/month spring water delivery — saving over $400 in the first year while eliminating 815 single-use plastic bottles. The consistent message across reviews is the water simply tastes better than alternatives at the same price point.
What Are the Common Complaints?
The most common Cloud RO complaint centers on annual filter replacement costs of $200-$250, which some users find high relative to comparable pitcher or under-sink filters. One user noted the filter cycle arrived around 580 gallons — faster than expected for their household. A second concern involves the app’s sensing method: the system tracks TDS and pulls local public water data rather than directly detecting individual contaminants.
Some users also cite installation difficulty. While most reviews describe the process as manageable, WaterFilterGuru noted the installation was ‘time-consuming’ and required basic DIY and plumbing skills to avoid mistakes. Cloud’s answer to this is a local installer directory — you can find a professional near you if self-installation feels like too much.
How Hard Is the Cloud Water Filter to Install?
Cloud RO installation typically takes 30-60 minutes, requires basic plumbing skills, and involves drilling into the water supply line — a process fully covered by Cloud’s step-by-step video guide. The system is battery-powered, so no electrical hookup is needed. Most reviewers describe the process as manageable for any household with basic DIY confidence.
Cloud provides a list of local installation professionals for users who prefer not to self-install. The installation guide covers each step: drilling, tube routing, app connection, and the initial flush cycle. After installation, users run the system for 5 minutes, repeat the flush, and the system is ready. It’s methodical — not complicated.
What Tools Do You Need to Install Cloud RO?
The Cloud RO package includes everything needed for standard installation: the RO unit, 2.8-gallon holding tank, stainless steel faucet, filter cartridges, battery pack, tubes, and all required fittings. Additional tubing is available from Cloud for basement or refrigerator hookup installations. No tools beyond standard household hardware are required for most installations.
After physical installation, the Cloud app setup takes only a few minutes. The app scans for the unit via Bluetooth, you name the device, and monitoring begins automatically. The app immediately starts tracking TDS readings, tank volume, and filter lifespan from the first pour. Think of it this way: if you’ve ever installed an under-sink water filter before, Cloud RO is easier.
How Much Does the Cloud Water Filter Cost?
Cloud RO retails at $649 at CloudWaterFilters.com and Amazon, with discount codes commonly reducing the price to $599; HSA/FSA funds can be applied, and Affirm financing is available for monthly payments. Free shipping covers the continental United States, Alaska, and Hawaii. Canadian customers must contact the company directly for shipping arrangements.
Annual filter replacement costs $200-$250 for a family of four — roughly $0.26 per gallon. This includes the battery pack replacement, which ships bundled with the RO membrane order approximately every 9-12 months. There are no subscription fees, monitoring fees, or hidden costs beyond filter replacements. What you see is what you pay.
Cloud RO Cost Breakdown:
| Item | Cost |
|---|---|
| System purchase | $649 (or $599 with discount) |
| Annual filter replacement | $200-$250 |
| Per-gallon cost | $0.26 |
| Battery replacement | Included with filter order |
| Shipping (continental US) | Free |
| Warranty | 1 year / 100% money-back |
Is Cloud RO Worth the Price?
Yes. Cloud RO pays for itself within the first year for households currently spending $40-$60 per month on bottled or delivered water — and eliminates hundreds of single-use plastic bottles in the process. One reviewer replaced a $55/month ($660/year) spring water delivery service with Cloud RO, saving money from month one after the initial system cost. The 100% money-back guarantee removes the financial risk from the purchase decision.
The 1-year warranty covers the full system. Returns are accepted within the warranty period for any reason. Cloud’s satisfaction guarantee is one of the broadest in the RO category. For most households making a long-term investment in water quality, the risk profile here is about as low as it gets.
Cloud RO vs Waterdrop G3P800: Which Is Better?
Cloud RO delivers matching lab-verified contaminant removal and NSF 58 certification as the Waterdrop G3P800 at approximately $400 less, making it the stronger value choice for most households. Both systems remove the same target contaminants at comparable rates. The real tradeoff is design: Waterdrop is tankless with a smaller cabinet footprint and a 3:1 efficiency ratio.
Cloud RO wins on: quieter operation, no power outlet dependency, fridge and ice maker compatibility, and better-tasting water from built-in remineralization. Waterdrop wins on: smaller cabinet profile and slightly better water efficiency. By comparison, if cabinet space is the deciding factor, Waterdrop G3P800 is still the right call. But if value, taste, and outlet-free operation matter more, Cloud RO is the stronger choice by a significant margin.
Should You Try the Cloud Water Filter at Eat Proteins?
Cloud RO is the top-ranked under-sink reverse osmosis system across multiple independent reviews, earning Wirecutter’s top pick status and a 9.24/10 from WaterFilterGuru through lab-verified 99% contaminant removal and best-in-class efficiency. No competing system at this price point matches its combination of remineralization, app monitoring, battery-powered operation, and 1:1 water efficiency. For households serious about clean water, this is the system to buy.
Our experts at Eat Proteins recommend Cloud RO for health-focused households concerned about PFAS, fluoride, and heavy metals in tap water. You get measurably cleaner water from day one. You don’t need an electrician. You don’t need a subscription. And you’re covered by a 100% money-back guarantee if it doesn’t work out.
Cloud RO is available at $649 at CloudWaterFilters.com — HSA/FSA funds apply, and Affirm makes monthly payments available. Use a discount code to bring the price to $599. Stop settling for unfiltered tap water and start knowing exactly what’s in every glass you drink.