iSpring CU-A4
Score: 72/100
Waterdrop TSU
Score: 78/100Rankings
The Waterdrop TSU is a compact, tankless under-sink filtration system that uses 0.01-micron ultrafiltration to remove contaminants like PFAS and fluoride while retaining beneficial minerals. Its zero-wastewater design and smart filter-life indicator make it an eco-friendly and convenient choice for space-constrained kitchens. However, the low flow rate and lack of TDS reduction limit its suitability for high-demand households or those needing absolute purity.
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 | 0.6 gallons per minutebest | |
6 months | 24 monthsbest | |
4best | 3 | |
1 yearsbest | 1 yearsbest | |
| ↓ lower better | 12.5 inchesbest | 18.62 inches |
| ↓ lower better | 4.5 inchesbest | 6.38 inches |
| ↓ lower better | 10.5 inchesbest | 18.39 inches |
0 percentbest | 0 percentbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | | |
|---|---|---|
Dimensions & Fit(3) | ||
Height (inches) | 12.5 inches | 18.62 inches |
Width (inches) | 4.5 inches | 6.38 inches |
Depth (inches) | 10.5 inches | 18.39 inches |
Performance & Filtration(5) | ||
Certifications | NSF/ANSI | NSF/ANSI 372 |
Contaminants Removed | Lead, Chlorine, PFAS, Arsenic, Heavy Metals, Chloramine, Hydrogen Sulfide, Rust, Sand, Dirt | Chlorine, Chloramine, PFAS, Lead, Fluoride, Heavy Metals, VOCs |
Flow Rate (gallons per minute) | 0.5 gallons per minute | 0.6 gallons per minute |
Filter Life (months) | 6 months | 24 months |
Filtration Stages | 4 | 3 |
Features & Accessories(1) | ||
Remineralization | false | true |
Installation & Compatibility(2) | ||
Installation Type | Under-sink | Under Sink |
Operating Pressure (psi) | 40 psi | 14.5-87 psi |
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.
Expert reviewers highlight the Waterdrop TSU's strong filtration performance and practical design, noting its superior ultrafiltration membrane that balances contaminant removal with mineral retention. The system is praised for its compact form factor and the convenience of the smart panel.
Customer feedback reflects strong satisfaction with the product, particularly regarding effective taste and odor removal and the reliability of the smart filter indicators. Users appreciate the easy installation and compact fit under standard sinks.
