Frizzlife PD800-TAM4 vs Waterdrop G3P800: Which to Buy

The Waterdrop G3P800 is the better under-sink reverse osmosis system overall, rated 3.4 to 3.1. The Waterdrop G3P800 leads on certification. The Frizzlife PD800-TAM4 wins on price and filter cost. The Frizzlife PD800-TAM4 costs $339.02 less ($509.98 vs $849).

Higher rated

Waterdrop G3P800

#6 in Tankless3.4Full review

For a busy kitchen that wants fast RO water and low waste from a certified system, and can pay for it.

Amazon $849

$849

Frizzlife PD800-TAM4

#12 in Tankless3.1Full review

For a household that wants fast mineralized RO water with low filter costs and does not need NSF 58 certification.

Amazon $509.98

$509.98

Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.

Which should you buy?

Choose the Waterdrop G3P800 for certification (certified to NSF/ANSI 58 vs not certified to NSF/ANSI 58; certified to NSF/ANSI 372).
Choose the Frizzlife PD800-TAM4 for price ($509.98 vs $849) and filter cost ($119 a year in replacement filters vs $160 a year in replacement filters).

Scores side by side

Each factor is scored 0-100 against the same fixed reference points for every tankless under-sink reverse osmosis system; a clear win is highlighted. How we rank explains each one.

Factor weight	Waterdrop G3P800	Frizzlife PD800-TAM4
Overall rating	3.4/5	3.1/5
Certification 25%	100 certified to NSF/ANSI 58	30 not certified to NSF/ANSI 58; certified to NSF/ANSI 372
Filter cost 20%	28 $160 a year in replacement filters	46 $119 a year in replacement filters
Water wasted 15%	100 3:1 pure to drain	95 2:1 pure to drain
Output 10%	71 800 gallons a day	71 800 gallons a day
Price 15%	5 $849	44 $509.98
Warranty 15%	0 1-year warranty	0 warranty not published, scored as none

Independent measurements

Waterdrop G3P800

Tested by	TDS reduction	Output	Pure to drain	Conditions
Water Filter Guru	95.5 %	886.5 gpd	2.2 :1	Tap Score lab: 776 ppm feed to 35 ppm output without remineralization (95.49%). Flow from a 12 oz fill timed at 9.14 s (0.62 gpm) with 58.3 F feed water. Ratio from a 64 oz draw (29 oz to drain); a 12 oz draw measured 1.5:1. Date is the review update date.