Water Filters for Microplastics: 6 Brands Tested and Ranked

The certifications that actually matter

Three independent certifications cover microplastic removal:

• NSF/ANSI 401 (“Emerging Compounds/Incidental Contaminants”) includes microplastics specifically (added 2018).
• NSF/ANSI 53 (“Health Effects”) covers particle reduction at >1 µm.
• NSF/ANSI 58, reverse osmosis system certification.

WQA and IAPMO offer equivalent independent certifications. If a filter doesn't carry one of these, the microplastic claim is essentially marketing.

Head-to-head: 12 popular filters

Certifications change; verify current status on the manufacturer's site or NSF's database before purchase.

Filter media chemistry, what actually catches the particle

Every filter on the comparison table removes microplastics through one of four mechanisms. Understanding which one is in your filter tells you what it can and can't catch, and where it'll fail first.

• Reverse-osmosis membrane. A semi-permeable membrane with effective pores of 0.0001 µm (0.1 nanometres). Water is forced through under pressure, particles and dissolved solids are rejected to a waste stream. RO catches everything from micrometre-scale particles down through the entire nanoplastic range. The same membrane removes lead, PFAS, fluoride, sodium, arsenic, and pharmaceutical residues, the only filter category that does. Tradeoff: needs plumbing or counter space, wastes ~1–3× as much water as it produces, removes beneficial minerals (some systems add an alkaline remineralisation stage).
• Carbon block. Solid extruded activated carbon with engineered pore size, typically 0.5–1 µm. Catches microplastics in that range and below by size exclusion, and chemical migrants (chlorine, BPA, pesticides) by adsorption. Does not catch nanoplastics below ~0.5 µm. Used in Clearly Filtered, Epic Pure, Multipure, Aquasana Clean Water Machine. Tradeoff: doesn't remove dissolved minerals or PFAS at high rates.
• Ceramic. Porcelain or earthenware element with pore size 0.2–0.5 µm, usually impregnated with silver to suppress biological growth. Used in Berkey's Black Berkey filters, Doulton, and gravity-fed systems. Catches microplastics >0.2 µm by size exclusion. Cleanable surface extends lifespan to years rather than months.
• Hollow-fibre membrane. Bundles of micro-tubes with 0.1–0.2 µm pore size. Used in LifeStraw Home and some emergency-prep filters. Catches microplastics, bacteria, and protozoa by size exclusion. Doesn't catch dissolved chemistry and is not effective against viruses.

Granulated activated carbon, the bed of small carbon granules in a standard Brita Classic, refrigerator filter, or whole-house pre-filter, has much coarser effective pore size (typically ~5–10 µm) and is engineered for taste and chlorine, not for particle exclusion. This is why a Brita Classic does not earn an NSF 401 microplastic certification while a Clearly Filtered pitcher does, even though both look like “a pitcher with carbon in it” from the outside.

Pore size vs particle size, what each filter actually catches

The 2024 Qian et al. PNAS study found bottled water averaged 240,000 plastic particles per litre, 90% of which were nanoplastics below 1 µm. The practical implication: if you care about nanoplastics specifically, and the evidence says you should, only reverse osmosis and distillation get them. Every other filter gets the micrometre fraction and misses the nano fraction.

What the filters don't remove (so you can decide if it matters)

Microplastic removal is one criterion. Buyers usually also want PFAS removal, lead removal, fluoride removal, and chlorination byproduct (THM) removal. The coverage gaps by filter type:

• Reverse osmosis (AquaTru, APEC, Waterdrop, iSpring): removes everything. PFAS, lead, fluoride, arsenic, pharmaceutical residue, nitrates. The only filter that removes them all.
• NSF 401 carbon block (Clearly Filtered, Epic, Multipure): removes PFAS (with the right cartridge), lead, chlorine byproducts. Doesn't remove fluoride or dissolved minerals.
• Ceramic + carbon (Berkey): Black Berkey filters remove lead and most heavy metals with the optional PF-2 fluoride filter add-on. Independent testing supports PFAS reduction but is not NSF-certified.
• Hollow-fibre (LifeStraw Home): good on bacteria and particles, weaker on dissolved chemistry. Pair with a carbon stage for full coverage.
• Standard Brita / granulated carbon / refrigerator filter: chlorine and taste only in most cases. Lead removal only on specific premium variants.

Cost per litre, the number that actually matters

A pitcher looks cheaper than an RO system until you do the math per litre of actually-filtered water. Estimates assume two people drinking ~2 L/day of filtered water (~1,460 L/year):

• Bottled water: ~$0.50–$1.00 per litre. $730–$1,460/year for the same volume. Worst per-litre option.
• Brita Classic: ~$0.02 per litre at chlorine-only level (not microplastic-rated).
• Clearly Filtered pitcher: ~$0.06 per litre (NSF 401). Year-1 ~$170 total (pitcher + 1 cartridge); year-2+ ~$80.
• AquaTru countertop RO: ~$0.11 per litre year-1 (system + filters); ~$0.07 per litre year-2+.
• APEC under-sink RO: ~$0.06 per litre year-1; ~$0.04 per litre year-2+.
• Big Berkey: ~$0.03 per litre across the system's expected ~5–10 year lifespan.

Over 5 years, an under-sink RO comes in at roughly the same per-litre cost as a Brita Classic but with NSF 58 certification including nanoplastic-range removal. The cost argument for Brita-class filters disappears the moment you compare per-litre properly.

Installation and maintenance, by filter type

• Pitcher (Clearly Filtered, Epic, Brita): zero install. Refill manually. Replace cartridges every 4 months (Clearly Filtered) to 2 months (Brita). The most common maintenance failure is forgetting to change the cartridge, performance drops sharply past the rated capacity.
• Countertop RO (AquaTru): plug in, fill the tank, press a button. Replace pre-filter every 6 months, main carbon every 12, RO membrane every 24. Filter-replacement subscription is the easiest path.
• Under-sink RO (APEC, Waterdrop, iSpring): 2–4 hour install (DIY-friendly if your sink has space; otherwise $150–$300 plumber). Pre-filter every 6 months, carbon every 12, RO membrane every 24, post-filter every 12.
• Gravity ceramic (Berkey): assemble at first use. Scrub the white ceramic filters with a Scotch-Brite pad every few months when flow rate slows. Black Berkey filters last ~6,000 gallons per pair (years of household use).
• Whole-house cartridge: not a microplastic solution by default, most whole-house systems run sediment and chlorine filters, not microplastic-rated stages. If you want point-of-use microplastic protection AND whole-house plumbing protection, layer an under-sink RO at the kitchen tap on top of whatever whole-house system you have.

What about just boiling it?

Worth knowing before you spend anything, because in the right water it is free and surprisingly effective. A 2024 study in Environmental Science & Technology Letters found that boiling tap water for five minutes and then filtering it once cool removes a large share of nano- and microplastics. The mechanism is incidental: as the water boils, calcium carbonate comes out of solution as limescale and the plastic particles co-precipitate with it, so straining out the chalky residue takes the particles with it.

The catch is that it depends entirely on how hard your water is, and the gradient is steep:

• 300 mg/L calcium carbonate (hard water) — about 90% removed.
• 180 mg/L — about 84%.
• 80 mg/L — about 34%.
• Under 60 mg/L (soft water) — roughly 25%, so barely worth the effort.

So this is a genuine free backstop in a hard-water region and close to useless in a soft-water one. It also does nothing for dissolved chemicals, and boiling every litre you drink is not practical at scale. Treat it as a bonus on top of a filter, not a replacement for one.

Best filter by buyer profile

If you rent or can't plumb in

AquaTru Classic ($450). Countertop RO; needs only a wall outlet; full NSF 401, 53, and 58 certifications. Removes 99%+ of microplastics including nanoplastics. The most upgradeable filter from any pitcher.

If you own and want the best whole-kitchen solution

APEC ROES-50 ($210). Under-sink 5-stage RO; installs in an afternoon; replaceable filters cost ~$80/year. Best long-term value for full microplastic and PFAS removal.

If you want simple, gravity-fed, off-grid capable

Big Berkey ($340). Stainless steel + ceramic + Black Berkey filters; no electricity required; lasts years; widely used and independently tested. Not NSF 401 certified (Berkey has chosen not to pursue certification) but third-party lab data is strong.

If you're budget-constrained (best ROI)

Clearly Filtered Pitcher ($90). NSF 401 certified for microplastics; 380 contaminants reduced; works with no installation. For under $100 this is the most defensible budget choice.

If you only care about chlorine/taste

A basic Brita Classic does the job, but please note it is nota microplastic filter despite often being assumed to be.

See: best water filter for microplastics (buying guide), how to filter microplastics from water, and microplastics in tap water.