APEC ROES-50 vs Waterdrop G3P800: Tank RO or Tankless RO?
These are the two reverse osmosis systems we point readers to most often, and they sit at opposite ends of the under-sink RO market: a $230 conventional five-stage system with a storage tank, and a $759 tankless unit that makes water on demand. Below, every spec comes from the manufacturer's own product page, with the URL we read.
Environmental Health Research
Should I buy the APEC ROES-50 or the Waterdrop G3P800?
Buy the APEC ROES-50 if you want certified RO performance for lead, arsenic, nitrate, fluoride and PFAS at the lowest price and have room under the sink for a 4-gallon tank. Buy the Waterdrop G3P800 if you want tankless on-demand flow (800 GPD), a published 3:1 pure-to-drain ratio, and NSF/ANSI 42, 53, 58 and 372 certification on one unit, and the ~$530 premium is acceptable.
- ✓APEC ROES-50: 5 stages, 50 GPD at 60 psi, 4-gallon tank, WQA Gold Seal certified, $230.99 (apecwater.com).
- ✓Waterdrop G3P800: 10-stage tankless, 800 GPD, 3:1 pure-to-drain, NSF/ANSI 42/53/58/372, $759 (waterdropfilter.com).
- ✓Both are one-year limited warranties; Waterdrop publishes filter life (6 / 12 / 24 months), APEC publishes intervals only on its Amazon listing (6–12 months pre-filters, 12–24 months membrane).
- ✓Neither unit needs a professional installer, but the ROES-50 tank takes real cabinet space.
Frequently asked questions
Does the APEC ROES-50 remove PFAS?▾
APEC's product page lists PFAS, PFOS and PFOA among the contaminants the system removes "up to 99%" of. The page cites WQA Gold Seal certification; its Amazon listing adds NSF 58 and 372 wording. We could not find a PFOA/PFOS-specific certification listing, so treat PFAS removal as a manufacturer claim backed by RO chemistry rather than a certified claim.
How much water does the Waterdrop G3P800 waste?▾
Waterdrop publishes a 3:1 pure-to-drain ratio, meaning roughly one cup down the drain for every three cups of filtered water. APEC does not publish a drain ratio for the ROES-50 on its product page.
Which one is better for a rental?▾
Neither is ideal for a strict no-modification lease because both need a faucet hole and a drain saddle. Between the two, the tankless G3P800 is easier to remove and take with you; the ROES-50 is cheaper to leave behind.
Spec sheet, side by side
| Spec | APEC ROES-50 | Waterdrop G3P800 |
|---|---|---|
| Type | 5-stage RO with storage tank | 10-stage tankless RO |
| Rated output | 50 GPD at 60 psi (30 GPD at 50 psi, 77°F) | 800 GPD (“fills a 6 oz cup in 5 s”) |
| Pure-to-drain ratio | not published | 3:1 |
| Tank | 4 gal, 11″ × 11″ × 15″ | none (tankless; “saves 70% under-sink space”) |
| System dimensions | 15.5″ L × 5.25″ W × 17″ H | not published on product page |
| Membrane | “High Rejection TFC” | G3P800-N2RO, 24 months / 2,200 gal |
| Filter life | Amazon listing: pre-filters 6–12 mo, membrane & post-filter 12–24 mo; not on apecwater.com | N1CF 6 mo / 550 gal · N3CB 12 mo / 1,100 gal · RO 24 mo / 2,200 gal |
| Certifications (as published) | WQA Gold Seal Certified System (apecwater.com); “NSF Certified 372 & 58” (Amazon title only) | NSF/ANSI 42, 53, 58, 372 |
| Claimed reductions | “up to 99%”: lead, arsenic, fluoride, chlorine, chromium, radium, PFAS/PFOS/PFOA, bacteria, viruses, VOCs | PFAS (99% PFOA/PFOS), fluoride, lead, chromium, heavy metals |
| Warranty | 1 year limited | 1 year, 30-day returns |
| Price seen | $230.99 | $759.00 (list $999.00) |
Sources read 2026-09-07: apecwater.com/products/roes-50, apecwater.com/pages/warranty, amazon.com/dp/B00I0ZGOZM, waterdropfilter.com/products/reverse-osmosis-system-g3p800, waterdropfilter.com/pages/nsf, waterdropfilter.com/pages/reduce-pfas-in-water.
What the numbers mean in a kitchen
Output. The ROES-50's 50 gallons per day is a membrane rating, not a faucet flow: the system trickles into a 4-gallon tank and you draw from the tank. That is plenty for a household's drinking and cooking water, but the tank drains to a dribble if you fill several large pots in a row, and the rating drops to 30 GPD at 50 psi, which is common in older homes and upper floors. The G3P800 skips the tank and filters at 800 GPD on demand, which is why Waterdrop quotes cup-fill time rather than a daily figure. In practice: the APEC is a “wait for it to refill” system, the Waterdrop is a “turn on the tap” system.
Wastewater. Every RO system sends concentrate down the drain. Waterdrop publishes 3:1 pure-to-drain for the G3P800; APEC publishes no ratio for the ROES-50, so we cannot compare them fairly. Conventional tank systems in this class are generally understood to waste more than modern tankless designs, but that is an industry generalization, not an APEC spec.
Certification. This is the clearest difference in the published record. Waterdrop lists NSF/ANSI 42 (aesthetic), 53 (health contaminants), 58 (RO systems) and 372 (lead-free materials) for the G3P800 on both its product page and its NSF page. APEC's own product page cites WQA Gold Seal, which is a legitimate third-party certification to the same NSF/ANSI standards, while the NSF 58 and 372 wording appears only in its Amazon title. Both are third-party certified; only Waterdrop states the standard numbers on its own site.
Consumables. Waterdrop prints filter life in months and gallons for all three cartridges. APEC gives intervals only in Amazon Q&A and spec table (“6 months” filter life cycle; pre-filters 6–12 months, membrane and post-filter 12–24 months). Replacement cartridges for a conventional five-stage system are commodity parts and generally cheap; proprietary tankless cartridges cost more per change but are changed less often. We have not priced either brand's replacement sets here because the prices change frequently.
Verdict by situation
- Renters. Both need a hole for the dedicated faucet (or a spare sprayer hole) and a drain saddle, so ask first. If permitted, the G3P800 is easier to remove and re-install elsewhere; the ROES-50 is cheap enough to leave behind. Renters who cannot modify plumbing should look at an NSF/ANSI 53 pitcher instead.
- Homeowners, small household. The ROES-50. Its output is adequate, the tank is a non-issue with cabinet space, and the price gap buys years of replacement filters.
- Homeowners, large household or cook-heavy kitchen. The G3P800. On-demand 800 GPD flow removes the tank-empty problem and the published 3:1 ratio means less water down the drain over thousands of gallons.
- PFAS. Both are RO systems, and RO is the right technology (why RO beats carbon for PFAS). Waterdrop publishes a 99% PFOA/PFOS reduction figure and an NSF/ANSI 58 listing; APEC lists PFAS among removed contaminants under WQA Gold Seal. If your city's UCMR5 results show PFOA or PFOS at or above 4 ppt, either is a large step down in exposure; the G3P800 has the more explicit paperwork.
- Lead. Both remove lead via the membrane; the G3P800 additionally carries NSF/ANSI 53 and 372. If lead is your only issue, a far cheaper NSF/ANSI 53 pitcher or under-sink filter does the job.
- Arsenic, nitrate, fluoride. RO is the standard home treatment for all three, and either system qualifies. Buy on price and space: the ROES-50.
- Taste only. Neither. A carbon filter is enough (chlorine taste and odor guide).
Where to buy
APEC ROES-50 (~$231)
Five-stage tank RO, WQA Gold Seal, one-year warranty. The value pick.
View APEC ROES-50 on Amazon →Waterdrop G3P800 and other tankless RO (~$759)
800 GPD tankless, 3:1 drain ratio, NSF/ANSI 42/53/58/372. The performance pick.
Shop Waterdrop RO systems →Other under-sink RO systems
Browse under-sink RO on Amazon →Disclosure: we may earn a commission from purchases through these links, at no extra cost to you. Specs are quoted from manufacturer pages, not from either merchant's marketing.
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