Compare Under-Sink Water Filters
Compare under sink water filters side by side. Filter by specs, price, and features.
Updated 2026-03-09
Independently reviewed
| Feature |
Waterdrop G3P800 Tankless RO
|
Aquasana AQ-5200
|
iSpring RCC7AK 6-Stage RO
|
APEC ROES-50
|
Aquasana AQ-5300+ Max Flow
|
Waterdrop Chromium Under-Sink
|
Express Water RO5
|
Brondell H2O+ Circle
|
Home Master TMA
|
PUR PLUS FM-3700B
|
|---|---|---|---|---|---|---|---|---|---|---|
| Rating |
9.3/10
|
9/10
|
8.9/10
|
8.6/10
|
8.8/10
|
8.5/10
|
8.6/10
|
8.4/10
|
8.7/10
|
8.2/10
|
| Check Deal → | Check Deal → | Check Deal → | Check Deal → | Check Deal → | Check Deal → | Check Deal → | Check Deal → | Check Deal → | Check Deal → | |
| Price | $449/one-time | $106/one-time | $220/one-time | $200/one-time | $149/one-time | $89/one-time | $249/one-time | $129/one-time | $349/one-time | $45/one-time |
| Type | Tankless RO | Carbon block | 6-stage RO | 5-stage RO | Carbon + prefilter | Direct connect | 5-stage RO | 3-stage carbon | RO with pump | 2-stage carbon |
| Contaminant Removal | 99.99% | — | — | — | — | — | — | — | — | — |
| Capacity | 800 GPD | 500 gallons | 75 GPD | 50 GPD | 800 gallons | 320 gallons | 75 GPD | 1,320 gallons | 75 GPD | 100 gallons |
| Waste Ratio | 3:1 | — | 4:1 | 4:1 | — | — | — | — | 1:1 or better | — |
| UV | Yes | — | — | — | — | — | Optional | — | — | — |
| Remineralization | Yes | — | Yes | — | — | — | — | — | — | — |
| Installation | Under sink | Under sink | — | DIY | — | No drilling | — | Under sink | — | Under sink |
| Faucet | Smart display | — | — | — | — | Uses existing | — | — | — | Included |
| Warranty | 1 year | 1 year | 1 year | 1 year | 1 year | 1 year | 1 year | 1 year | 1 year | 90 days |
| Certification | — | NSF | — | — | NSF | — | — | — | — | NSF |
| Removes | — | Lead, PFOA, PFOS, microplastics | Lead, arsenic, fluoride, PFAS | Lead, fluoride, chlorine | Lead, PFOA, chlorine | Chlorine, lead, sediment | Lead, arsenic, fluoride | Chlorine, lead, cysts | 99% including fluoride | Lead, chlorine |
| Filter Life | — | 6 months | — | — | 6 months | — | — | 2 years | — | 3 months |
| Electricity | — | None | — | — | — | — | — | — | — | — |
| Stages | — | — | 6 (including alkalinity) | — | — | 3 | 5 (+ UV/alkaline options) | — | 3 | — |
| Tank | — | — | 3.2 gallon | 3 gallon | — | — | 3.2 gallon | — | 3.2 gallon | — |
| Parts | — | — | — | USA | — | — | — | — | — | — |
| Flow Rate | — | — | — | — | 0.72 GPM | — | — | 0.5 GPM | — | — |
| Prefilter | — | — | — | — | Sediment | — | — | — | — | — |
| Design | — | — | — | — | — | Compact | — | Compact circle | — | — |
| Alkaline | — | — | — | — | — | — | Optional | — | — | — |
| Pump | — | — | — | — | — | — | — | — | Permeate pump | — |
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Our Methodology
We test each under-sink filter for contaminant reduction, installation ease, and long-term cost. No manufacturer has editorial influence.
Frequently Asked Questions
Can I install an under-sink filter myself?
Yes. Most under-sink filters come with DIY installation kits. You'll need to connect the filter to the cold water line (often via a saddle valve or tee), mount the filter housing, and install the faucet (if included). Basic plumbing skills help; most installations take 30-60 minutes. RO systems are more complex due to the tank and drain line. If you're uncomfortable, professional installation runs $100-200. The Waterdrop Chromium is the easiest—no faucet drilling, just connect to existing plumbing.
Do under-sink filters remove fluoride?
Carbon filters do not remove fluoride. Only reverse osmosis and distillation remove fluoride effectively. RO systems like the iSpring RCC7AK, APEC ROES-50, Waterdrop G3P800, and Home Master TMA remove 99%+ of fluoride. If you want to reduce fluoride (e.g., for health preferences or children), you need an RO system. If you're fine with fluoride in tap water, a carbon filter is sufficient for chlorine and lead.
What's the best under-sink filter for renters?
The Waterdrop Chromium is ideal because it requires no drilling—it connects to your existing faucet. You can remove it when you move. The Aquasana AQ-5200 is another option if your landlord allows a small faucet hole; many consider it a minor modification. Avoid RO systems with tanks if you're in a small rental—they take significant under-sink space. Check your lease before any permanent modifications.
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