The certified pick for a large home or a small business on a private well. It costs a lot, but the dose is measured and certified.
Amazon $3,840The Viqua PRO20 is the better UV water purifier overall, rated 3.6 to 3.0. The Viqua PRO20 leads on certification, warranty and lamp life. The Viqua VP950M costs $1,700 less ($2,140 vs $3,840).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Viqua’s largest monitored Professional unit, for a farm, a big property on one well or light commercial use. Overkill for a typical home.
Amazon $2,140Which should you buy?
- Choose the Viqua PRO20 for certification (NSF/ANSI 55 Class A vs not NSF/ANSI 55 certified; flow rated at a stated 40 mJ/cm² dose), warranty (5-year warranty vs 3-year warranty) and lamp life (18,000 hour mercury lamp vs 9,000 hour mercury lamp).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every over 12 GPM UV water purifier; a clear win is highlighted. How we rank explains each one.
| Factor weight | Viqua PRO20 | Viqua VP950M |
|---|---|---|
| Overall rating | 3.6/5 | 3.0/5 |
| Value 25% | 16 $192 per GPM ($3,840, 20 GPM at 40 mJ/cm²) | 48 $82.31 per GPM ($2,140, 26 GPM at 40 mJ/cm²) |
| Certification 20% | 100 NSF/ANSI 55 Class A | 30 not NSF/ANSI 55 certified; flow rated at a stated 40 mJ/cm² dose |
| Monitoring 20% | 100 UV intensity sensor, lamp failure alarm, shutoff valve, lamp change countdown | 100 UV intensity sensor, lamp failure alarm, shutoff valve, lamp change countdown |
| Lamp life 10% | 44 18,000 hour mercury lamp | 6 9,000 hour mercury lamp |
| Warranty 25% | 44 5-year warranty | 22 3-year warranty |
Specifications
| Viqua PRO20 | Viqua VP950M | |
|---|---|---|
| Disinfection | ||
| Rated flow | 20 GPM at 40 mJ/cm² | 26 GPM at 40 mJ/cm² |
| NSF/ANSI 55 | Class A | No |
| Lamp | Mercury | Mercury |
| Lamp power | 140 W | 90 W |
| Lamp life | 18,000 hours | 9,000 hours |
| Monitoring | ||
| UV intensity sensor | Yes | Yes |
| Lamp failure alarm | Yes | Yes |
| Lamp change countdown | Yes | Yes |
| Shutoff valve | Yes | Yes |
| Build | ||
| Chamber | 316L stainless steel | 304 stainless steel |
| Ports | 1.2 in | 1.5 in |
| Maximum pressure | 125 psi | 125 psi |
| Voltage | 120 V | 120 V |
| Warranty | 5 years | 3 years |
