APEC Ultimate RO-90 Reverse Osmosis Drinking Water System Review

Author: Rory Mullan - Published: 2021/07/12 - Updated: 2022/06/06

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This product review features the APEC Ultimate RO-90 reverse osmosis system.

APEC is known for making sound water filtration systems at an affordable price tag, and their Ultimate series has been hailed as one of the best from the company.

The APEC Ultimate RO-90 reverse osmosis system is the flagship product from the brand, popular for providing double the amount of clean water than standard reverse osmosis units.

Therefore, the RO-90 seems like the perfect choice for larger families or groups of people living together. With 90 gallons per day water flow theoretically, it definitely falls in the high output category.

So, should you get the APEC Ultimate RO-90 for your home? Find the nitty-gritty of this drinking water system in the guide below.

For Reviews & Comparison of Our Favorite Reverse Osmosis Systems Click Here!

APEC RO-90 Reverse Osmosis System Review – Main Specs

APEC Ultimate RO-90 reverse osmosis system


See More Product Images at amazon.com

  • For tap and disinfected well water[1]
  • Filter stages: 5
  • Daily filtration capacity: 90 gallons (theoretical)
  • Recovery rate: roughly 25%
  • Estimated filter replacement cost per year: $75
  • System dimensions: ‎ 16 x 5.25 x 17.5 inches, 25 Pounds
  • Required water pressure: 40-85 psi
  • Max TDS: 2,000 ppm
  • NSF: 58


At the beginning of our APEC reverse osmosis review, a few highlights:

5 Stages of Filtration

The first filter is a polypropylene sediment element that captures rust, stray particles and other sediments. Removing these larger impurities from water ensures they don’t end up clogging the reverse osmosis membrane. And it improves water aesthetics.

In the second and third stages, there are activated carbon filter blocks that reduce the taste, cloudiness and odor created by chemicals like chlorine. It’s also vital to reduce the chlorine level in this step, or it otherwise damages said RO membrane.

Finally, the membrane removes all the different contaminant types found in our water supplies these days. It rejects up to 99.0% of arsenic and 98.3% of cadmium[2] which can be detrimental to your health. Additionally, it removes 98.3% chromium 6 and 99% chromium 3 to ensure your drinking water is free of the health-hazardous transition metal. At the same time, it removes fluoride, lead and rids your water of 99% of TDS.

After the reverse osmosis membrane comes a final carbon post-filter that removes any impurities that might have been left behind. It also rids the water of any foul taste that may has been picked up in the storage tank.

High Water Output

Do note that 90 gallons is a theoretical figure, and you can’t expect to get the exact amount of output daily from the APEC Ultimate RO-90 since factors like backpressure can lower the flow of water.

Despite this, the reverse osmosis system is ideal for offering sufficient water for cooking and drinking.

Low-Cost Replacement Filters

New filters are widely available and don’t cost much.


  • Being a premium water filtration system, this APEC reverse osmosis system impresses with its multi-stage filtration and contaminant reduction ability.
  • It has a WQA Gold Seal Certification for NSF Standard 58, ensuring that its parts and materials are safe and have optimum structural integrity. Plus, it’s a testament to the system’s contaminant removing ability.
  • It’s important to keep in mind that every RO system wastes some water, and this one does too. The recovery rate is 1:3, which is better than average for such systems.
  • The filters used are made in the US and last for a year, which reduces the need for frequent replacement. Moreover, they are easy to find in the market and don’t cost much.
  • The manufacturer offers a one-year limited warranty for the RO-90, which expands to two years if you register.


  • Some customers who had previously used the RO-90 said they experienced bad taste in the water, which might be due to the storage tank.
  • Although APEC has a certified support team, it can be hard to reach them in case of a problem or question.
  • Some users also reported their systems malfunctioning or ceasing to work altogether.


You have to install the APEC Ultimate Series RO-90 just like a standard under-the-sink reverse osmosis system. For this, you must drill a hole in the countertop or the kitchen sink to hold the dispenser.

The company has added a step-by-step guide in the box, so it shouldn’t be hard for you to set up the filtration system quickly. Typically, it should take anywhere between an hour or two.

  1. Assembling the Main System
    1. Start by removing the wrappings on the 3 pre-filters.
    2. Put the cartridges into their filter housings.
    3. Hand twist the housings onto the filter module. Tighten with the wrench.
  2. Establishing the Feed Water Connection
    1. Turn off the incoming cold water supply.
    2. Install the feed water adapter after applying four to five wraps of Teflon tape.
    3. Screw on the needle valve after applying six to 8 wraps of Teflon tape.
    4. Slide compression nut and plastic sleeve onto the red tubing. Push the tubing into the needle valve port. Tighten with a wrench.
  3. Installing the Drain Saddle
    1. The drain saddle needs to be positioned on the drain pipe above the trap, horizontally or vertically. Drill a ¼” hole in the drain line.
    2. Install the drain saddle with the holes aligned. Tighten the screws.
    3. Push in the ¼” drain tubing.
  4. Installing the RO Faucet
    1. First, you need to drill a new hole in your kitchen sinktop or use an existing one. Choose a flat area that’s convenient to access.
    2. Mount the faucet.
    3. Connect the dispenser tubing to the RO system’s output port.
  5. Positioning the System
    1. Place the under sink filter in a spot that allows for maintenance.
    2. The water storage tank can lie on its side.
  6. Connecting the System
    1. Use the red tubing to connect the cold water supply to the RO module.
    2. Use the yellow tubing to connect the RO module to the storage tank.
    3. Use the clear tubing to connect RO module to dispenser.
    4. Use the black tubing to connect the RO membrane to the drain saddle.
  7. Starting the System
    1. Open the cold water supply and the needle valve. Check for leaks.
    2. Open the tank valve and allow the tank to fill within the next few hours.
    3. Drain the full tank by opening the RO dispenser.
    4. Let the tank refill a second time.


Normally, there’s little to no maintenance for this RO system. However, you should change the filters as per the following timelines:

  • Change the stage 1, 2 and 3 filters every year.
  • Change the membrane every three to five years if you’re using city water and two to three years in case of well water.
  • Replace the carbon post-filter every three to five years.

What we like is that costs are reasonable.

What’s Included

Here’s what you’ll find in the package:

  • RO system
  • Pre-filters + housings
  • Filter housing wrench
  • TFC reverse osmosis membrane
  • Post-filter
  • Feedwater adapters
  • Drain saddle
  • Faucet adapter
  • Chrome dispenser
  • Color-coded tubing
  • 4-gallon water storage tank
  • Tank valve
  • Teflon tape
  • Manual

APEC Reverse Osmosis Review – Conclusion & Best For

If you have a large household with more than 5-6 occupants, you definitely can depend on the APEC Ultimate Series RO-90 reverse osmosis drinking water system best for providing you a sufficient flow of clean, contaminant-free and non-smelly water.

Although there are better systems in the market in our opinion, we give the RO-90 a thumbs-up!

If you have questions about our APEC reverse osmosis system review please leave a comment below!

Further Reading


Meet Rory Mullan

Rory Mullan Rory has joined the Water Masterz team as a contributing writer. He has covered all sorts of topics in the last several years.

Outside of his writing work, Rory enjoys photographing the Irish landscape and making music!

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