Waterdrop M6SL Mineral Countertop RO review
By Daryna Klochko · Published · Specs checked Oct 14, 2026 · 
Scores 9.5/10, tied for 1st of the 9 countertop RO systems we track. At $329 it costs the same as the category median of $329.
Low running costs: about $70 a year in cartridges, the lowest among the 9 countertop RO systems that state one
You need a certified health claim: its listing covers TDS only, unlike 4 of the 9 countertop RO systems
- Price
- $329
- Certified for
- TDS
- Flow
- Not stated
- Cartridge life
- 1,100 gal claimed
- Cost per year
- $70
- Warranty
- 1 year
Certification
Listed by IAPMO under NSF/ANSI 58 for TDS, checked Oct 14, 2026. Waterdrop also claims 5 more substances that are not in the listing. Search the IAPMO listings
- TDS
Waterdrop also claims Chlorine, Lead, PFOA/PFOS, Arsenic, Fluoride: brand claims, not in a certifier listing.
The contaminants or other substances removed or reduced by this water treatment device are not necessarily in your water. Listing checked on Oct 14, 2026. What a listing means and what it doesn't
Specs and sources
Checked Oct 14, 2026 · source under each valueFiltration
Cartridges and install
Buying
Warranty, returns and shipping
Warranty: 1 year. Returns: 30 days. Shipping: not stated by the brand. Source: waterdropfilter.com, checked Oct 14, 2026.
Source: waterdropfilter.com, checked Oct 14, 2026.
Compared with similar countertop RO systems
All 9 countertop RO systems →| Model | Price | Certified for | Cost per year | Warranty | Score | Where to buy |
|---|---|---|---|---|---|---|
| APEC Water RO-CTOP-C Portable Countertop RO | $269.95 | Brand claims only | $90 | 1 year limited | 9/10 | Check price → |
| Bluevua ROPOT-Lite | $299 | Lead · Cadmium +2 | $108 | 1 year limited | 9.5/10 | Check price → |
| Express Water ROC001 5-Stage Countertop RO, Instant Hot | $299.99 | Brand claims only | $139 | 1 year | 8.75/10 | Check price → |
| Waterdrop M6SL Mineral Countertop ROTHIS MODEL | $329 | TDS | $70 | 1 year | 9.5/10 | Check price → |
| SimPure Y7P-BW Countertop RO | $369.99 | Brand claims only | $100 | 1 year | 9/10 | Check price → |