ZIP vs U1: Which RKIN RO System Fits Your Kitchen in 2026?

Two countertop RO systems, different strengths

RKIN makes two zero-installation countertop reverse osmosis systems: the ZIP (Zero Installation Purifier) and the U1 Space-Saving 4-in-1 Water Filter System.

Both sit on your counter, both use RO membranes, and neither needs a plumber. But they serve different needs and budgets. Here's the practical breakdown so you can pick the right one.

Quick comparison table

When the ZIP is the better pick

The ZIP is built for one job: clean, certified RO water with zero friction.

• You want certified RO filtration (NSF/ANSI 58) at the lowest entry price.
• You only need room-temperature filtered water.
• Counter space is tight — the ZIP has a slightly smaller footprint.
• You're in a rental, dorm, or office where simplicity matters most.
• Budget is the priority — $299 vs $670 is a meaningful difference.
• You don't need app control or hydrogen-enriched water.

The ZIP works like a coffee maker: fill the bottom pitcher, press the button, walk away. In about 15 minutes you have half a gallon of purified water. The unit turns itself off. That's it.

Available in two editions: AlcaPure (alkaline, pH 7-8 with calcium and magnesium) or OnliPure (zero TDS for absolute purity).

When the U1 is the better pick

The U1 is a daily-driver water station that does more than filter.

• You want hot water on demand (tea, baby formula, instant oatmeal) without a kettle.
• You want chilled water without a fridge pitcher.
• Hydrogen-enriched water with negative ORP (-340) interests you.
• You want UV sterilization as an extra safety layer.
• App monitoring and remote control appeal to you (U1-W model).
• You're replacing both a water filter and a hot/cold dispenser — the U1 consolidates both.

The U1 also includes a 5-stage filtration system with an alkaline remineralization post-filter. The intelligent touch panel shows real-time water quality, hydrogen content, and filter status.

If you add the 2-Year Filter Bundle, you get 3 full years of filters for about $338 — roughly $113/year.

Setup and daily use

Both systems require zero installation. No plumbing, no faucet adapters, no tools.

ZIP daily routine: Fill bottom tank from faucet → press button → wait ~15 min → dispense from top tank. Repeat as needed.

U1 daily routine: Fill removable tank → place on system → select hot, cold, or room temp from touch panel → dispense. The U1 holds more water and produces it faster for family-sized daily use.

Both fit on a standard kitchen counter at 9.5 inches wide. The U1 is about 3 inches taller and 2.5 inches deeper.

Filter replacement cost comparison

ZIP: The replacement filter kit runs about $50-70/year depending on usage. Filters are easy to swap — no tools needed.

U1: Individual filter replacements run about $80-120/year. The 2-Year Filter Bundle ($338) covers 3 years of use at ~$113/year and includes RO membrane, hydrogen PEM modules, and pre/post filters.

Both systems have LED indicators that tell you when filters need changing.

What about undersink RO?

If you own your home and want filtered water directly from your faucet, consider the Flash Undersink RO System. It installs under the sink, operates on water pressure alone (no electricity), and delivers RO water on demand through a dedicated faucet. Typical install takes 30-60 minutes.

The Flash is a good fit for homeowners who want permanent, out-of-sight filtration. ZIP and U1 are better for renters or anyone who wants to avoid installation entirely.

FAQ

How long does it take to set up the ZIP or U1?

Both take under 5 minutes. Unbox, rinse the filters per the included instructions, fill the water tank, and start filtering. No plumbing or tools needed for either system.

How much do replacement filters cost per year?

ZIP filter kits run about $50-70/year. U1 individual filters run $80-120/year, or roughly $113/year with the 2-Year Filter Bundle. Both systems include filter change indicators so you know exactly when to swap.

Is there a taste difference between the two?

Both produce high-quality RO water. The ZIP offers a choice between AlcaPure (alkaline with minerals) and OnliPure (zero TDS). The U1 includes alkaline remineralization by default plus optional hydrogen infusion, which some users prefer for taste and antioxidant properties.

Can I use ZIP or U1 in an RV or vacation rental?

Yes. Both are portable, countertop systems that only need a power outlet and access to tap water. The ZIP is lighter and slightly more compact for travel use.

Which one removes more contaminants?

Both use RO membranes that reduce TDS, fluoride, lead, and other dissolved contaminants. The ZIP holds IAPMO R&T certification to NSF/ANSI 58. The U1 adds UV sterilization as a supplemental treatment step.

RKIN has been making pure drinking water accessible since 2009. Free shipping in the Continental U.S. Questions? Call 1-800-803-4551 or live chat Mon-Fri 9 AM-5 PM.