Viqua VP600M
#5 in Over 12 GPMFull review
The monitored VP600, for a large well home or small business where a failed dose has to stop the water. Buy the plain VP600 if someone checks the system regularly.
Amazon $1,735$1,735
The Viqua VP600M is the better UV water purifier overall, rated 3.0 to 2.6. The Viqua VP600M leads on certification. The HQUA TWS-24S costs $1,235.01 less ($499.99 vs $1,735).
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.
HQUA TWS-24S
#9 in Over 12 GPMFull review
A cheap high flow unit for a large home that wants a UV backstop in a small space. The rating is unverified, so size it generously.
Amazon $499.99$499.99
Which should you buy?
- Choose the Viqua VP600M for certification (not NSF/ANSI 55 certified; flow rated at a stated 40 mJ/cm² dose vs not NSF/ANSI 55 certified, and no UV dose published).
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 VP600M | HQUA TWS-24S |
|---|---|---|
| Overall rating | 3.0/5 | 2.6/5 |
| Value 25% | 42 $96.39 per GPM ($1,735, 18 GPM at 40 mJ/cm²) | 65 $52.08 per GPM ($499.99, 9.6 GPM at 40 mJ/cm², from 24 GPM at an unstated dose taken as 16) |
| Certification 20% | 30 not NSF/ANSI 55 certified; flow rated at a stated 40 mJ/cm² dose | 0 not NSF/ANSI 55 certified, and no UV dose published |
| Monitoring 20% | 100 UV intensity sensor, lamp failure alarm, shutoff valve, lamp change countdown | 50 monitoring not published (neutral score used) |
| Lamp life 10% | 6 9,000 hour mercury lamp | 50 lamp life not published (neutral score used) |
| Warranty 25% | 22 3-year warranty | 0 warranty not published, scored as none |
Specifications
| Viqua VP600M | HQUA TWS-24S | |
|---|---|---|
| Disinfection | ||
| Rated flow | 18 GPM at 40 mJ/cm² | 24 GPM |
| NSF/ANSI 55 | No | No |
| Lamp | Mercury | Mercury |
| Lamp power | 58 W | 80 W |
| Lamp life | 9,000 hours | - |
| Monitoring | ||
| UV intensity sensor | Yes | - |
| Lamp failure alarm | Yes | - |
| Lamp change countdown | Yes | - |
| Shutoff valve | Yes | - |
| Build | ||
| Chamber | 304 stainless steel | 304 stainless steel |
| Ports | 1 in | 1 in |
| Maximum pressure | 125 psi | - |
| Voltage | 120 V | 120 V |
| Warranty | 3 years | - |