APEC Ultimate RO-CTOP Portable Reverse Osmosis Drinking Water System Review

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APEC’s RO-CTOP is a portable countertop reverse osmosis filter system designed to provide healthy and great-tasting drinking water right from your kitchen tap. It’s compatible with most standard faucets – pull-out, sprayer, and special designer models won’t work – and makes use of a 4-stage filtration process to reduce up to 99% of chlorine, arsenic, chromium-6, copper, fluoride, lead, radium, and many other potential water contaminants, says APEC.

Ready to dig a little deeper? Let’s go!



Price: $$
Filter Stages: 4
Filtered Water: Around 2 Gallons Per Hour
NSF Certifications: 42
Annual Cost: ~$95-130

Our Rating

APEC RO-CTOP Reverse Osmosis System – Key Features

Filtration stage 1 uses a 5-micron polypropylene sediment pre-filter to remove larger particles like rust, protecting the rest of the system from clogging.

At stage 2, a coconut shell granular activated carbon filter adsorbs chlorine, unpleasant tastes and odors, cloudiness, and colors. In addition, it reduces VOCs and other chemicals commonly found in our water supplies. By the way, the filter was certified against NSF Standard 42 for an average chlorine reduction of more than 95%.

Stage 3 is the most important. Here the semipermeable reverse osmosis membrane comes into play. It’s a Dow FILMTEC model rated at 90 gallons per day that achieves a TDS rejection rate of up to 98-99%. Simply put, it does the bulk of the contaminant removal even blocking bacteria and viruses. However, we miss a performance data sheet with specific reduction rates for contaminants like lead.

The fourth stage features another coconut shell granular activated carbon filter. This is to remove any residual tastes. If you want, you can substitute this stage with a remineralization filter that automatically adds calcium carbonate to the water for better taste and a more balanced pH (alkaline water). This will turn the APEC RO-CTOP into the APEC RO-CTOP-PH. Or, if you already own the APEC RO-CTOP you could purchase the calcite remineralization filter separately.

Another optional upgrade is a silver aluminum case for better looks which makes a lot of sense considering that the RO system sits on your countertop all day. It makes much less of an eye sore.

All in all, you can expect between 2 to 3 gallons of purified water per hour, depending on feed water condition and pressure.

Required water pressure: 35 to 90 psi, although below 40 psi an additional pump is recommended.


For us, the main reason to buy a countertop RO system instead of a regular under sink unit is that no installation is required. You just plug and play, or drink we should say. This makes any version of the APEC RO-CTOP great for anyone who cannot make permanent changes to the plumbing system or where there is not enough space for a large holding tank.

Just keep in mind that, although the system comes with a bunch of adapters, it only works with standard faucets with a removable aerator.

We also like the compact and lightweight design for high portability. The system weighs only 7 lbs. Do you like to travel?

More pros:

  • Diverter allows you to switch between filtered and unfiltered water without the need to disconnect the system.
  • Only BPA-free materials used.
  • Filters are Made in USA.
  • Quick-connect fittings allow for fast filter replacements.
  • You get a 1-year limited manufacturer warranty.

The APEC RO-CTOP – learn more on amazon.com


The APEC RO-CTOP literally hooks up in less than 2 minutes – easy! Again, faucet adapters are included in the package.

Then, all you have to do is flush the membrane and filters for 10-15 minutes before first use and you are good to go.

Filter/Membrane Replacement

The quick connect fittings allow for fast filter changes. Here’s how:

  1. Disconnect tubing by pushing in and holding down the fitting collet ring against the fitting.
  2. Pull out the tubing.
  3. Discard old filter.
  4. Push the tubing all the way into the fittings of the new cartridge. To test for a secure connection gently pull back on the tubing.

The whole process is also explained in the manual in great detail.

Tip: Replace one filter at a time to avoid mix-ups.

How often do filters need to be replaced?

  • Sediment pre-filter – Every 6 to 8 months or 600 to 800 gallons, whichever comes first
  • Carbon pre-filter – Every 6 to 8 months or 600 to 800 gallons, whichever comes first
  • RO membrane – About every 2 to 3 years if pre-filters are changed according to schedule
  • Carbon post-filter – Every 2 to 3 years
  • Optional calcite filter – Every 6 months

Cost? We estimate around $95-130 per year for the APEC RO-CTOP and $130-180 for the APEC RO-CTOP-PH – more than what you pay with the competition.

By the way, the filters and membrane have the industry standard size of 10”, meaning you can switch to cheaper off-brand models if need be.

About Membrane Replacements

The safest method to determine the condition of an RO membrane is by measuring output water TDS a.k.a. total dissolved solids (using a TDS meter).

If the permeate reads 3 to 10 percent of the feed water TDS, the membrane is working well. As soon as the TDS creeps up to more than 15% replacement is due.


Our main issue with the APEC RO-CTOP is that the tubing to and from the filters/system is prone to leaking. For some people it became brittle after several weeks of use, while for others the tubing burst open or blew off completely.

Above that, the system is a bit too pricey for our liking, especially the maintenance part considering that only the activated carbon filter is certified for chlorine reduction and that’s it. Speaking of, as mentioned before, we generally would have preferred more testing or certifications against NSF standards.

And lastly, there’s no dispenser. Water exits the unit via a small tube which is not the most elegant solution.

APEC RO-CTOP Review: Our Verdict + Best for

The APEC RO-CTOP portable countertop reverse osmosis water filter system is easy to install, use, and maintain, it’s great for on the go and small apartments, and it provides great-tasting water – the majority of people compliment the pristine flavor. But it’s more costly to purchase and maintain compared to similar competitor models, thus 3.5 stars!

The APEC RO-CTOP is best for people looking for a compact RO water filter to put on their countertop at home or use on the go.

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This completes our APEC RO-CTOP review. If you have any questions please don’t hesitate to leave a comment below!

About the Author Alexandra Uta

Alex is a content writer with an affinity for research and a methodical attention to detail. Her writing interests have included many different topics, water treatment among them, which have encompassed varying writing styles.
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