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Under sink reverse osmosis

APECROES-50

Cheap tank RO with low filter costs and output that depends on your water pressure

By Facts checked

Source-based analysis, not hands-on testing. Our method

Cofounder of Superhuman Chambers · About the author.

The verdict

The ROES-50 is a five-stage under-sink RO system with a 4-gallon tank and faucet for $230.99. It makes sense if your water pressure is near 60 psi and you want filters that cost about $55 a year. The catch is a one-year warranty and a WQA claim that couldn't be matched to a certifier listing.

The trade-off

Output falls to 30 GPD at 50 psi, and APEC's contaminant claims aren't backed by a confirmed certifier listing.

APEC ROES-50, manufacturer product image
Photo: APEC.Source ↗

Model reviewed: ROES-50 Essence 5-stage, 50 GPD

$230.99

US price, checked

Check price at APEC

No affiliate commission on this link. Check the exact variant before buying.

About this price

List price on APEC's product page on Oct 13, 2026, before tax. The page labels it "Sale price" but shows no regular price, and APEC's store listing shows no regular price either, so it isn't a markdown. It's sold in one configuration, shown as in stock. The ROES-50X bundle with extra pre-filters lists at $252.99 but shows as unavailable. APEC advertises free shipping on orders of $49 or more, limited to the 48 contiguous states.

A GOOD FIT FOR

You want RO water at one kitchen sink for little money, and your water pressure is near 60 psi.

  • You want RO drinking water at one sink for about $230 upfront, and a tank under the sink is fine
  • Municipal or well water that stays within 40 to 85 psi, 40 to 100°F and 2,000 ppm TDS
  • You're comfortable drilling a 1/2 in faucet hole and fitting a drain saddle yourself
  • A household that drinks a few gallons a day and can wait 1.7 to 3 hours for the tank to refill

THINK TWICE IF

  • You need certified reduction of lead, fluoride or PFAS, since no certifier listing for those claims was found
  • Your water is microbiologically unsafe or untested, since the manual says it then needs disinfection before or after the system
  • Your water pressure is around 50 psi or lower, where APEC rates it at 30 GPD
  • Drain water matters to you: APEC's FAQ puts under-sink systems at about 3 gallons wasted per gallon made
  • You want more than a one-year warranty
What still needs checking
  • The ROES-50's own pure-to-drain ratio
  • Whether a WQA or IAPMO listing covers the ROES-50, and which contaminants it lists
  • The membrane's TDS rejection rate
  • How much water the tank delivers at typical home pressure, since the manual's 3.2 gallons is at 80 to 90 psi
  • Test data behind the "Guaranteed to Remove" contaminant list
  • Installed cost if you hire a plumber
  • Price of O-rings, and whether the $14.95 Essence post-filter is the ROES-50's exact stage 5 part

The practical details.

Specifications for APEC ROES-50
Exact variantROES-50 Essence 5-stage, 50 GPD
Rated output50 GPD at 60 psi and 77°F (about 1.8 gal an hour); 30 GPD at 50 psi
Drain waterNot published for the ROES-50; APEC's FAQ gives about 3:1 for under-sink systems in general
Tank4 gal total volume (bladder and air space); about 3.2 gal bladder capacity at 80 to 90 psi; refills in 1.7 to 3 hours (FAQ) or 2 to 3 hours (manual)
Filter lifePre-filters every 6 to 12 months; membrane and stage 5 every 2 to 4 years (the manual says 2 to 3)
Feed water limits40 to 85 psi; 40 to 100°F; up to 2,000 ppm TDS; pH 2 to 11
CertificationAPEC claims WQA certification for TDS reduction; no NSF listing; WQA listing not confirmed
PowerNone; the manual describes a non-pumped system
DimensionsSystem 15.5 in L × 5.25 in W × 17 in H. Tank 11 × 11 × 15 in. Package weight 26 lb. The manual says to allow about 17 × 6 × 18 in for the system and 11 in across and 18 in tall for the tank.
MaterialsFive stages: a 5-micron polypropylene sediment filter, two 10-micron carbon block filters, a high-rejection TFC RO membrane and a 10 in coconut-shell refining carbon filter for taste. The kit includes a lead-free faucet, food-grade tubing, a stainless steel check valve and a flow restrictor. APEC doesn't state the tank's material.

Before you buy

InstallationAPEC sells it as a do-it-yourself install and links a general RO installation video

APEC sells it as a do-it-yourself install and links a general RO installation video. It connects to the cold-water line only, using the included 1/2 in feed adapter and valve. You drill a 1/2 in hole for the standard faucet (1-1/4 in for an air-gap faucet) and a 1/4 in hole in the drain pipe for the drain saddle. Tubing is color-coded with quick-connect fittings. Feed water must be 40 to 85 psi, 40 to 100°F, under 2,000 ppm TDS and pH 2 to 11. The warranty doesn't cover damage from installation.

WarrantyOne year from the purchase date, covering defects in materials and workmanship

One year from the purchase date, covering defects in materials and workmanship. Used filter cartridges and membranes are excluded. It's void if you aren't the original purchaser, or if you run it outside normal municipal or well water conditions. The manual also voids it if you bought the unit used or from anyone other than APEC or an authorized dealer. Coverage depends on changing filters as the manual directs, and damage from non-APEC parts is excluded. A claim needs a return goods authorization number, and you pay to ship the unit to APEC. APEC's FAQ promises lifetime technical support.

ReturnsYou can return it within 30 days of the invoice date with an RMA number…

You can return it within 30 days of the invoice date with an RMA number, and it must reach APEC within 15 days of the RMA. You get a full refund, less shipping and handling, only if it's unused in unopened packaging. Opened but unused costs a 10% fee, missing parts or damage 15% to 45%, and used but not defective 50%. You pay return shipping unless the return is APEC's error or a defect. The policy covers only orders from apecwater.com.

More about this assessment

The ROES-50 is a five-stage under-sink reverse osmosis system with a 4-gallon tank and a lead-free faucet, for $230.99. Filters cost about $55 a year if you change the pre-filters yearly. APEC rates it at 50 GPD with 60 psi feed pressure, dropping to 30 GPD at 50 psi. The product page calls it WQA certified, but that couldn't be matched to a certifier listing. The long removal list, including lead, fluoride and PFAS, comes with no published test data. The warranty is one year.

Strengths on paper

  • $230.99 includes the tank, a lead-free faucet, the drain saddle and the feed adapter
  • Cheap filters: $29.95 for the three pre-filters and $79.99 for a complete set with the membrane
  • Wide feed-water limits: 40 to 85 psi, up to 2,000 ppm TDS and pH 2 to 11
  • No power needed, since the manual describes a non-pumped system
  • Color-coded tubing and quick-connect fittings for a DIY install

Limitations

  • The WQA claim couldn't be matched to a certifier listing, and APEC's FAQ names its Ultimate line, not the Essence line, as WQA certified
  • The long removal list, including lead, fluoride and PFAS, comes with no published test data
  • One-year warranty that excludes used filters and the membrane, and is void if you buy used or from an unauthorized seller
  • Output depends on pressure: 50 GPD at 60 psi falls to 30 GPD at 50 psi
  • APEC doesn't publish a pure-to-drain ratio for the ROES-50
  • A used return that isn't defective loses 50%, and you pay return shipping
  • Takes cabinet space: about 17 × 6 × 18 in for the system plus an 11 in wide tank

What it costs to own.

Adjust the assumptions for your use. Missing costs stay unknown.

PLAN YOUR OWNERSHIP COSTS

What will it cost to own?

Change the assumptions to fit your use. Leave an unknown cost blank. Add water, subscriptions, cleaning, shipping and taxes if they apply. Use average operating power, not the maximum rating.

3-year known subtotal

$395.90

Incomplete: installation. This is not the full ownership cost.

Energy component: $0.00

Purchase + installation + years × (annual consumables + annual other) + watts/1000 × hours/day × 365 × years × $/kWh. Annualized allowances, not an exact replacement schedule. Excludes taxes, shipping, finance and resale unless entered.
Replacement parts & cost assumptions

Recorded recurring parts and refills:

  • FILTER-SET-ES pre-filter set (stages 1 to 3): $29.95 every 12 months. One sediment filter and two carbon block filters. APEC says to change them every 6 to 12 months. The set's page says it lasts over 6 months, up to 3,000 gallons. It's shown as a sale price with no regular price.
  • FILTER-MAX-ES50 complete filter set (stages 1 to 5): $79.99 every 24 months. The three pre-filters plus the RO membrane and the stage 5 carbon filter. The set's page puts the membrane and stage 5 at 2 to 4 years. The manual says 2 to 3 years on city water and 2 years for the membrane on well water.
  • MEM-ES-50 RO membrane (stage 4): $39.95. Sold on its own for the ROES-50. The membrane's page gives no replacement interval.
  • Bundle of two Essence pre-filter sets (stages 1 to 3): $49.95. Price and name from APEC's store search listing. That's about $25 a set, which helps if you change pre-filters every 6 months.
  • FI-ES-TCR-QC Essence inline carbon post-filter: $14.95 every 24 months. APEC's page says it's for Essence systems and calls it a polishing post-filter. It doesn't name the ROES-50 or coconut-shell carbon, so it may not be the exact stage 5 part. The page says to change it every 2 to 4 years.
  • Filter housing O-rings: cost not recorded every 12 months. The manual says to replace them every year or with each pre-filter change. A price wasn't observed.
  • Purchase is the $230.99 list price on APEC's product page on Oct 13, 2026, before tax.
  • Annual consumables assume a $29.95 pre-filter set in year one and a $79.99 complete set in year two, then repeat. That's $109.94 every two years, or $54.97 a year. It replaces the pre-filters yearly and the membrane and stage 5 every two years.
  • If you change pre-filters every 6 months, it's three $29.95 sets plus one $79.99 complete set every two years, or about $84.92 a year. O-rings aren't priced and aren't included.
  • Installation is unknown. APEC sells it as a DIY install, and plumber labor isn't priced.
  • Energy is zero because the manual describes a non-pumped system and lists no power supply. Drain water adds to your water bill, but that cost depends on local rates and isn't estimated.
  • There's no subscription, so other yearly costs are $0.

Evidence & sources.

Do water filters work? Our evidence review grades the research as Strong. That grade is about the claim, not about this product.

  • CertificationNSF's drinking water treatment unit database returned no listings for company name APEC or trade name ROES-50.1011 This rules out NSF certification, not certification by another body. WQA's product directory blocked access, and IAPMO's directory couldn't be searched, so any WQA or IAPMO listing and its scope are unconfirmed.
  • Manufacturer claimAPEC's product page shows a WQA logo, calls the ROES-50 WQA certified and says it was tested for TDS reduction.1 No certificate number, standard or listing link is given. APEC's FAQ names its Ultimate line as WQA certified and doesn't mention the ROES-50. The owner's manual doesn't mention WQA or NSF/ANSI 58.
  • Manufacturer claimAPEC says the ROES-50 removes up to 99% of contaminants and lists lead, arsenic, fluoride, PFAS, nitrate, bacteria and viruses among them.112 No test standard, lab or per-contaminant results are published for the ROES-50. The owner's manual gives a lower general figure: RO units remove 90 to 95% of contaminants and impurities. It also says not to use the system on microbiologically unsafe water or water of unknown quality without disinfection before or after it.
  • Manufacturer claimAPEC rates output at 50 GPD with 60 psi feed water at 77°F and 30 GPD at 50 psi. Its FAQ says the tank refills in about 1.7 to 3 hours, and the manual says 2 to 3.1512 Manufacturer ratings, not independent measurements. Real output and drain volume vary with pressure, temperature and TDS.
Sources (13)
  1. ROES-50 - Essence 5-stage 50 GPD Reverse Osmosis Water System for Drinking Water, WQA Certified APEC Water Systems · manufacturer · checked Oct 13, 2026
  2. ROES-50 listing on APEC's store (price, regular price, SKU and availability) APEC Water Systems · manufacturer · data file · checked Oct 13, 2026
  3. Warranty APEC Water Systems · manufacturer · checked Oct 13, 2026
  4. Shipping and returns APEC Water Systems · manufacturer · checked Oct 13, 2026
  5. F.A.Q. Reverse Osmosis Water Filtration Systems APEC Water Systems · manufacturer · checked Oct 13, 2026
  6. APEC RO Replacement Filters Complete Filter Set for ESSENCE ROES-50 System (Stages 1-5) APEC Water Systems · manufacturer · checked Oct 13, 2026
  7. APEC RO Replacement Filters Pre-filter Set for All ESSENCE Reverse Osmosis Systems (Stages 1-3) APEC Water Systems · manufacturer · checked Oct 13, 2026
  8. APEC Reverse Osmosis Membrane 30-50 GPD for ESSENCE ROES-50 Systems APEC Water Systems · manufacturer · checked Oct 13, 2026
  9. APEC store search listing for ROES-50 (ROES-50X, filter bundle and part prices) APEC Water Systems · manufacturer · data file · checked Oct 13, 2026
  10. NSF drinking water treatment units listings: company name APEC NSF · certifier · checked Oct 13, 2026
  11. NSF drinking water treatment units listings: trade name ROES-50 NSF · certifier · checked Oct 13, 2026
  12. APEC ROES-50 Owner's Manual (Essence RO system), copy hosted by ESP Water Products APEC Water Systems · manufacturer · checked Oct 13, 2026
  13. APEC ESSENCE 10 Inch Inline Carbon Filter With Quick Connect, 5 Micron APEC Water Systems · manufacturer · checked Oct 13, 2026

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About this review. The facts on this page come from manufacturer pages and certification listings, checked Oct 13, 2026. The sources are listed above.

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