Waterdrop G3P800 review
Waterdrop G3P800 Tankless Reverse Osmosis System (800 GPD)
By Tom Calder
A tankless RO and the only system in this group certified for both lead and PFOA/PFOS: IAPMO R&T lists it to NSF/ANSI 58 for lead, fluoride, TDS and more, and its carbon block to NSF/ANSI 53 for PFOA and PFOS. 800 GPD means no wait for a tank. It needs an outlet under the sink and a drain line.
- Best for
- Certified for lead and PFOA/PFOS in one tankless system
- Skip it if
- You rent and can't drill or tap a drain
as of Nov 14, 2026, 5:36 PM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.We earn a commission if you buy through the retailer links on this page. It doesn't change our verdict. How we make money →
Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Certified (IAPMO R&T) for lead under 58 and PFOA/PFOS under 53
- 800 GPD tankless: no storage tank
- 3:1 pure to drain
Worth knowing
- Needs an outlet under the sink
- Large unit for small cabinets
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Who shouldn't buy this
Don't buy it if you rent and can't drill or tap a drain: a certified pitcher is simpler.
Key specs
| Type | Tankless under-sink, 10 stages |
| Rated output (maker) | 800 GPD |
| Pure to drain (maker) | 3:1 |
| Needs power | Yes |
| Certification (certifier's listing) | IAPMO R&T: NSF/ANSI 58 (incl. lead, fluoride, TDS), 53 (PFOA/PFOS), 42, 372 |
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the US price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for The same certified claims for a smaller household
as of Nov 14, 2026, 5:36 PM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Best for A cheaper tankless RO with a mineral stage
as of Nov 14, 2026, 5:36 PM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Best for A compact tankless RO from Frizzlife's own store