iSpring CU-A4
Score: 72/100
Waterdrop 15UB
Score: 88/100Rankings
The Waterdrop 15UB is a highly rated under-sink filter offering 2 years of filtration and strong certification against PFAS and lead. Its main limitation is the lack of TDS reduction and cold-water-only operation. It is best suited for renters and homeowners seeking a low-maintenance, high-capacity solution.
The iSpring CU-A4 is a compact, tankless 4-stage ultrafiltration system that removes up to 99% of 700 contaminants while retaining beneficial minerals and producing zero wastewater. It lacks independent third-party testing data and does not reduce TDS, which are limitations for users seeking comprehensive purification. It is best suited for apartment dwellers and RV owners with limited under-sink space who prioritize mineral retention.
| Attribute | | |
|---|---|---|
0.5 gallons per minute | 0.75 gallons per minutebest | |
6 months | 24 monthsbest | |
4best | 3 | |
— | 19,000 gallonsbest | |
1 yearsbest | 1 yearsbest | |
| ↓ lower better | 12.5 inchesbest | 16.34 inches |
| ↓ lower better | 4.5 inches | 3.46 inchesbest |
| ↓ lower better | 10.5 inches | 3.66 inchesbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | | |
|---|---|---|
Dimensions & Fit(3) | ||
Height (inches) | 12.5 inches | 16.34 inches |
Width (inches) | 4.5 inches | 3.46 inches |
Depth (inches) | 10.5 inches | 3.66 inches |
Performance & Filtration(7) | ||
Certifications | NSF/ANSI | NSF/ANSI 42, 53, 372; IAPMO |
Contaminants Removed | Lead, Chlorine, PFAS, Arsenic, Heavy Metals, Chloramine, Hydrogen Sulfide, Rust, Sand, Dirt | PFAS, PFOA/PFOS, Lead, Chlorine, Heavy Metals, Sediment, Odor |
Flow Rate (gallons per minute) | 0.5 gallons per minute | 0.75 gallons per minute |
Filter Life (months) | 6 months | 24 months |
Filtration Stages | 4 | 3 |
Filtration Technology | Ultrafiltration | Multistage |
TDS Reduction (percent) | 0 percent | false percent |
Installation & Compatibility(3) | ||
Installation Type | Under-sink | Under Sink, Push-to-Connect |
Operating Pressure (psi) | 40 psi | 60 psi |
Installation Time (hours) | 1 hours | 0.05 hours |
Products in the top-left offer the best value (high score, low price).
The search results consist primarily of manufacturer product pages and retailer listings, with no independent professional reviews or third-party testing data included. Consequently, there is no expert editorial assessment available to validate the system's actual performance relative to the manufacturer's claims regarding contaminant removal and durability.
The provided data does not contain user reviews, customer testimonials, or recurring feedback patterns from everyday consumers. While Home Depot lists 81 customer questions and answers, the specific content of this user feedback is not included in the research data.
Professional reviewers recognize the Waterdrop 15UB for its certified safety and ease of use, highlighting the IAPMO certification and zero-leak performance.
Everyday users express strong satisfaction with the simplicity of installation, space-saving design, and noticeable improvement in water taste.
