AquaTru Carafe
The widest certified reduction we’ve tested, PFAS, lead, and fluoride, in a countertop unit that needs no plumbing at all.
Jump to pick ›Waterdrop G3P800
The best RO to plumb in: tankless, strong flow, NSF/ANSI 58 certified, and it never runs dry the way a tank system can.
Jump to pick ›iSpring RCC7AK
A genuine whole-system NSF 58 certification plus an alkaline remineralization stage, for about half the price of a premium RO.
Jump to pick ›Reverse osmosis is the most thorough home filtration there is, the one method that reliably removes fluoride, arsenic, and dissolved solids along with lead and PFAS. Every system here does that well, so the real choices are where it goes (countertop needs no plumbing, under-sink hides in the cabinet) and whether it adds minerals back for taste. Those are our three picks above; the full field is ranked below.
How they compare
Every RO system we’ve reviewed, ranked by our overall 5-point score. They all remove the big contaminants; what differs is how they install, whether they remineralize for taste, and the strength of their certification.
| # | System | Overall | Install | Minerals | Certified | Price |
|---|---|---|---|---|---|---|
| 01 | AquaTru CarafeBest overallCountertop RO | 4.7 | None | No | Cert | $350–450 |
| 02 | AquaTru ClassicBest for familiesCountertop RO | 4.5 | None | No | Cert | ~$449 |
| 03 | Waterdrop G3P800Best under-sinkTankless RO | 4.4 | DIY | No | Cert | $350–450 |
| 04 | Home Master TMAFC-ERPBest tasteRO + minerals | 4.3 | DIY | Yes | Parts | ~$480 |
| 05 | iSpring RCC7AKBest valueRO + alkaline | 4.2 | DIY | Yes | Cert | $200–240 |
| 06 | APEC Ultimate RO-90Under-sink RO | 4.2 | DIY | No | Cert | ~$265 |
| 07 | APEC ROES-50Under-sink RO | 4.1 | DIY | No | Cert | $180–230 |
| 08 | Aquasana OptimH2OMost certifiedRO + Claryum | 4.1 | DIY | Yes | Cert | ~$450 |
| 09 | Culligan Reverse OsmosisDealer RO | 3.8 | Pro | No | Cert | Quote |
Install: None = countertop, no plumbing · DIY = under-sink, self-fit · Pro = dealer-installed. Minerals = a remineralization stage that adds taste back. Cert = whole-system NSF/ANSI 58 (or WQA Gold Seal); Parts = individually NSF-listed components, not a whole-system listing. Scores are on our 5-point scale; see how we rank. Prices are typical street price and move often.
Our six reverse osmosis picks
The award winners in full, with what each does best and who it’s for. Tap any name for the complete review.
AquaTru Carafe
Our highest-rated filter of any kind. A countertop RO that needs no plumbing, certified by IAPMO to NSF/ANSI 53 and 58 for the widest range we’ve seen, PFAS, lead, and fluoride included.
AquaTru Classic
The same certified RO water as the Carafe, in a bigger unit with larger tanks. The pick if you want countertop RO and go through a lot of water each day.
Waterdrop G3P800
The best RO to plumb in. Tankless, so it saves cabinet space and never runs dry, with strong flow and NSF/ANSI 58 certification.
Home Master TMAFC-ERP
Fixes RO’s flat taste by adding minerals back twice, and a permeate pump cuts water waste. One tool-free filter change a year keeps upkeep low.
iSpring RCC7AK
A genuine whole-system NSF/ANSI 58 certification and an alkaline remineralization stage, for around half the price of a premium RO.
Aquasana OptimH2O
The deepest certification list here: NSF/ANSI 42, 53, 58, and 401 across 90+ contaminants, with certified fluoride and PFAS. Filters cost more to run.
How to choose a reverse osmosis system
Reverse osmosis is the right tool when you need to remove fluoride, arsenic, or dissolved solids, not just chlorine and taste. Once you’ve decided you need RO, two questions remain: where it goes, and how much waste and upkeep you’ll accept.
Countertop or under-sink?
Countertop RO (like the AquaTru) needs no plumbing, sits on the counter, and moves with you, ideal for renters. Under-sink RO hides in the cabinet and dispenses from a dedicated faucet, with either a storage tank or a tankless design that saves space and never runs dry.
Waste, minerals, and certification
RO sends some water to the drain; a permeate pump or a tankless design cuts that waste sharply. It also strips minerals, so systems that add them back taste better. And look for a genuine system-level NSF/ANSI 58 certification, not just certified parts.
Not sure RO is what you need? Our best drinking water filters overview compares RO against pitchers, carbon, and whole-house systems.
Common questions
What’s the best reverse osmosis system?
For most people, the AquaTru Carafe is our top overall pick: a countertop RO with the widest certified reduction and no plumbing. If you want RO permanently plumbed in, the tankless Waterdrop G3P800 is the best under-sink option, and the iSpring RCC7AK is the best value.
Does reverse osmosis remove fluoride, PFAS, and arsenic?
Yes, and that is its main advantage over carbon filters. Reverse osmosis reliably reduces fluoride, arsenic, and total dissolved solids, along with lead and PFAS. If any of those is your reason for filtering, RO is the surest route. See our fluoride guide and PFAS guide for the certified shortlist.
How much water does reverse osmosis waste?
A conventional system sends roughly three to four gallons to the drain for every gallon of purified water. Newer designs cut that a lot: a tankless RO like the Waterdrop G3P800 or a permeate-pump system like the Home Master TMAFC-ERP can get close to one to one. It is worth checking the ratio before you buy.
Is RO water bad for you because it removes minerals?
No. Reverse osmosis does strip beneficial minerals, but the amount you get from water is small compared with food, so healthy diets are unaffected. The real downside is taste: demineralized water can taste flat. Systems with a remineralization stage, such as the Home Master, iSpring, and Aquasana OptimH2O, add minerals back for better flavor.
Do I need a plumber to install one?
Not always. A countertop RO like the AquaTru needs no installation at all, just a power outlet and a faucet to fill it. Under-sink systems add a dedicated faucet and a drain connection, which a confident DIYer can finish in one to two hours, though many people hire a plumber. Tankless units are the tidiest since there is no storage tank to fit.