• Proved to remove up to 99% of 1000+ contaminants, including arsenic, chlorine, fluoride, lead, heavy metals, bacteria & virus, etc.
  • Durable enough
  • A longer filters’ lifespan
  • Safe materials used
  • Certified by WQA
  • Designed and made in the USA
  • Easy installation and replacing filters
  • Comes with a 2-year manufacturer warranty

The APEC Water Systems RO-90 is another under sink water filter from APEC you can trust and it is rated high and receives many positive customer reviews. If you are looking for the best under sink water filter, this one can be reliable.

Its functions and structure are similar to APEC ROES-50, but its water output per day can be up to 90 gallons. If you need plenty of pure water to cook and drink every day, this one is the ideal one. 90 GPD is the highest water output for an under sink water filtration system. You can use pure water from this system for coffee, tea, ice, cooking, or even an aquarium. That’s will be safe to consume pure water from this system.

This system is 5-stage water filter and 1 gallons of pure water causes another 3 gallons of waste water. This filtering level is average. Considering its lower price, it is competitive to others.

Plus, it comes with everything for setup. Anyone with basic DIY skills can install it with ease. And it also comes with a water faucet and a storage tank.

Filtration System Design

Each of these filters has their own housing. Therefore, before replacing one filter, you need to remove its filter housing. Well, because of water in the housing, you should pay attention to this while replacing filters.

The stage 1 to 3 filters are common water filters which should be replaced every 6 months. When it is time to replace them, you can use a “C” spanner to loosen them first, and then unscrew them by hand. And then take out the old one and replace the new one. After that, screw its housing and use the “C” spanner to tighten it. It is advised to grease the housing threads to allow you to twist it off with ease when you need to change filters next time.

As RO system, the RO filter is the stage 4. It is replaced every 2 to 3 years, so the stage 5 filter is. Well, it is difficult to know when it is the exact time. Therefore, a TDS test meter can help. This one doesn’t have an indicator, so a TDS test meter is a good tool to test water and allow you to know the exact change time.

This filters is designed to remove 99% of 1000+ contaminants, including arsenic, chlorine, fluoride, lead, heavy metals, bacteria & virus, etc. Therefore, it can offer you pure enough water to drink and cook.

Water Efficiency

In order to flush the RO membrane or create back pressure, some feed water will be wasted and wasted will be sent down the drain. Well, this system produces each gallon of pure water and also produces 3 gallons of waste water. If you are sensitive to waste water, you can use the waste water for non-drinking use, like watering flowers or gardens. Of course, you need some additional tubing to get the waste water from its container.

How much waste water it will produce depends on the water pressure of the feed water. If water pressure is too low, more waste water will be produced and you may need a permeate pump to raise the pressure. Well this one doesn’t come with it and you need to buy separately.

Ease of Installation

This system is designed to be compact, so it doesn’t take up space, allow you install in a very small under counter space. Of course, you can install it anywhere you like, just if there is a water feed line nearby. The installation is not complicated and anyone with basic DIY skills can do the job. All the tools it needed can be found easily in most households. The color-coded tubes also make the installation much easier. You will not be confused by these tubes.

This systems works perfectly if the incoming water pressure is between 40 and 80 psi. Therefore, before installing, you need to know the water pressure. If the water pressure is too low or too high, you need to prepare other things. A permeate pump is essential for a lower water pressure, while a pressure regulator is essential.

Of course, it comes with a very detailed user manual, but the following videos can help you know the detailed steps to install it:

Like I said before, it is not a high-end RO system, it doesn’t come with an indicator, so that you need to guess when you need to change its filters. Well, another way is to have a TDS test meter which allows you to test the water from this system. If there is a very obvious dropdown on the water quality, it is a sign of changing its filters.

Although it is compact and can be installed under most counters, it also needs some extra space for changing the filters. This is because using the spanner wrench to tighten or loosen the filter housing requires some operating space. Before installation, you need to pay attention to this.

Pros & Cons


  • Highest water output per day: up to 90 gallons
  • In expensive filters that lower the changing cost
  • Removes up to 99% of 1000+ contaminants
  • Easy installation design
  • A longer life of this RO membrane
  • Comes with lead-free faucet and 4 gallon water storage tank
  • Include a 1-year manufacturer’s warranty
  • Made in the USA


  • An average ratio of filtered water to waste water
  • 1 filter per housing makes a little difficult to replace filters
  • Doesn’t include a UV light filter or a remineralization filter
  • Doesn’t have an indicator to monitor the water quality


Question: Can this system remove fluoride?

Answer: Yes, it can. According to the WQA’s testing, it can remove up to 97.7% of fluoride.

Question: How often to replace its filters? And what is the cost?

Answer: Well, the pre-filter set which has 3 filters in the first stages should be replaced every 1 year. And it costs about $39. The complete filter replacement costs $119. We highly recommend to change it every 3 to 5 years.

Question: Can this system be hooked to an ice maker on my fridge

Answer: Yes, it can, but it needs proper connections.

Question: Can anyone install it or it requires professional installation?

Answer: Don’t worry about it. This system is designed to be easy to install. Anyone with basic DIY skills can install it. A very comprehensive installation manual is in the package. And you also can watch a video on the youtube for a step-by-step instruction.


The most impressive feature of this APEC RO-90 is its highest water output per day: up to 90 gallons. Therefore, this RO system is ideal for those who need more water every day.

Well, this system doesn’t have a modular design, so the changing process is a bit difficult than other modular filters, like xxx. Every coin has two sides. The cost of the replacement filters is very affordable.

Of course, this one is not a high-end model, but the high quality water it produces and the highest water output make it also competitive. Therefore, as one of the most cost-effective reverse osmosis systems, if you value cost-effectiveness, it is one of the best choices.

APEC Water Systems RO-90 Reverse Osmosis System Review

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