NU Aqua Countertop RO with Hot Water

Looking for the ultimate solution to pure, hot water at your fingertips? Let me introduce you to the NU Aqua 4-Stage Countertop Reverse Osmosis System with Hot Water Dispenser.


This innovative system blends advanced filtration and instant hot water convenience. In this comprehensive review, we'll take a look at its standout features, benefits, and pros and cons. I’ll also share my firsthand experience with it. By the end, you’ll have all the information you need to decide if it’s a good fit for you.

Just want to know how much it costs? 

Click here to check the current price at NU Aqua Systems. (Use code MARGE5 for 5% off your order.)

What are the key features of the NU Aqua Countertop RO System?

Countertop filtration system with hot water dispenser

The NU Aqua Countertop Reverse Osmosis System is a complete filtration system that won’t take up any valuable space under your kitchen sink. It requires absolutely no installation, so there’s no need to mess with your plumbing.

This water filter dispenses purified water at the touch of a button, and even has a built-in heater for instant hot water.

You can select from five different temperatures or touch the baby formula button for 100° water, the perfect temperature for feeding baby.

4-stage filtration

Add potable tap water to the tank, and the NU Aqua automatically sends the water through four stages of filtration on its way to the pure water tank.

  1. Sediment filter - Made of polypropylene (PP) cotton, this filter captures large particles like sediment, sand, silt, and rust. Trapping these particles at the start extends the life of the RO membrane.
  2. Carbon block filter - Contaminants like chlorine, VOCs, iron, parasites, pesticides, and other organic chemicals are captured by this filter.
  3. Reverse osmosis membrane - Microscopic pores in the membrane allow water to pass through while blocking extremely small particles of dissolved solids, heavy metals, fluoride, arsenic, and other impurities.
  4. Granular Activated Carbon (GAC) filter - This final “polishing” stage ensures that the water is free of any bad taste, odor, or color.

The first two stages are combined in one filter cartridge. Likewise, stages three and four are combined in a single cartridge.

Touch screen display panel

All the controls and indicators are on a user-friendly display panel on the front of the system.

A built-in TDS (Total Dissolved Solids) meter takes a reading of the water as it enters and exits the filtration system. Those numbers are displayed on the panel.

NU Aqua Countertop RO display panel

There’s also a filter life indicator that shows how much life is left in your filters. Each cartridge has its own reading, which is helpful because they don't always last the exact same length of time.

Next on the screen is the water volume setting, where you can choose the amount of water you want to dispense - 4, 8, 12, or 16 ounces. There is no continuous flow function.

Then you have the temperature setting. Your choices are 68°, 100°, 160°, 175°, or 200°F. 

In the bottom row of the display, you have a child lock button, the dispense button, and a formula button, which sets the temperature to 100°F. That means you don’t have to try to remember which temperature is best for making baby formula.

Other indicators on the screen tell you when the system is filtering, when the holding tank needs to be refilled, and when the purified water tank is too low to dispense, so you have to wait until it refills.

Remarkable wastewater ratio

If you’re concerned about conserving water, you’ll definitely want to consider the NU Aqua countertop reverse osmosis system.

This model only wastes one gallon of water for every five gallons of purified water it produces. That’s a ratio of 5:1! 

Compare this to conventional under-the-sink RO systems, which can waste up to four gallons of water for each gallon of purified water (ratio of 1:4). That’s impressive!

What contaminants does it remove?

According to the NU Aqua website, this filter system removes 99.99% of 1,000+ harmful substances including viruses, bacteria, chemicals (PFOA/PFOS, pharmaceuticals), heavy metals (lead, arsenic, etc), chlorine, TDS, fluoride, nitrates/nitrites, and more.

They also say that "an independent laboratory certified it to NSF standard 58." Standard 58 pertains specifically to reverse osmosis filtration systems.

NU Aqua does not currently publish third party lab test results on their website, but a typical RO system does removes all those substances. If they ever do post their lab test results, I'll link to it here.

For further reading: NSF/ANSI 58: Reverse Osmosis Drinking Water Treatment Systems

Like all reverse osmosis filters, the NU Aqua Countertop removes beneficial minerals along with what we would consider to be contaminants. This can result in the water tasting a bit “flat” and can make it slightly acidic.

How big is the NU Aqua Countertop RO? What is the capacity?

Overall, the NU Aqua countertop system measures 14”H x 10.5”W x 15”L

It will fit under the average kitchen cabinet, but you don’t want to put it there. The water storage tank is in the back of the unit, and you have to lift it straight up all the way to refill it. So, it’s impossible to get the tank out if it’s under a cabinet. 

You’ll have to put it somewhere else like on an island or table, or you could put it sideways on the counter.

Also, it needs to be near an electrical outlet so you can plug it in. The power cord is about 4-½ feet long.

You have a 7-⅛ inch clearance between the drip tray and the dispenser nozzle. That’s not enough room for a tall water bottle.

Take the drip tray out, and you have 8-¼ inches of clearance.

NU Aqua Countertop RO with drip tray removed

How much water does it hold?

The storage tank holds one gallon, and the pure water tank holds about two quarts. That doesn’t sound like much, but it does filter quickly, so it should be adequate for a small family.

How long do the filters last?

There are two filter cartridges that you’ll need to replace every so often.

Stage 1 (CF filter) lasts about 9-12 months.

Stage 2 (RO filter) lasts about 18-24 months.

Exactly how long they last depends on the quality of your tap water and the volume of water you use. 

You can buy the cartridges individually or bundled (at a savings of 5%) from NU Aqua.

Replacement filters for NU Aqua Countertop RO

What's in the box?

You’ll receive the complete system with the tank and filters pre-installed, a drip tray, and instruction manual.

How do you install it?

This system comes with the filter cartridges preinstalled, and there is nothing to install.

But, you will need to flush the system the first time you use it and every time you replace the filters.

To do this, you’ll fill the storage water tank, plug the unit in, and then follow the steps outlined in the owner’s manual. Allow yourself about 30 minutes to do all the setup.

How do you operate the NU Aqua Countertop RO System?

Using the NU Aqua is easy.

Once you fill the holding tank and put it back in place, the filtration process starts automatically. After about five minutes, there will be enough filtered water in the pure water tank for you to dispense a glass full.

To dispense, first select the volume and temperature you want, then touch the dispense button. You can stop it from dispensing by touching the button again.

When there’s not enough purified water to dispense, the “Wait” indicator lights up. The system starts filtering and fills up the pure water tank again.

The cycle repeats until the holding tank water is used up. At that point, the “Refill” indicator lights up and you’ll hear some beeps. That’s your signal to refill the tank with tap water.

NU Aqua Countertop RO system storage tank

TIP: Dump out the water that’s left in the tank before you refill it. This is the wastewater, and you don’t want to keep sending it through the system. The instruction manual doesn’t tell you this, but if you don’t do it, it’ll shorten the life of your filters.

My experience using the NU Aqua Countertop RO

For the most part, the system functioned like I expected it to and I enjoyed using it. There are a few quirks that I want to mention, though.

Setup confusion

I had some trouble with the initial setup and flushing, and I don't think it was user error because I tried it twice.

During setup, a series of numbers (01 through 08) appear on the display, and you’re supposed to do what the instruction manual says at each step.

Well, when I did it, it skipped 01 through 03 and went straight to 04. The rest of the sequence didn’t go right, so I just kept dispensing and refilling the tank until I had sent three full tanks through the system.

Then I thought I’d try taking out the filters, putting them back in, and resetting the system like you do when you replace the filters. It didn’t go right this time, either. It skipped number 02, and when I was supposed to refill the tank, it was only about half empty.

Maybe it would have been better if the designer had skipped the fancy electronic guided setup and just said to flush the system three times before using! 

This was annoying, but I was confident that the system was flushed, and then I was able to go on to use the filter without any problems.

Temperature not accurate

One thing I really like about the NU Aqua is being able to have instant hot filtered water for making tea. Curious about the accuracy of the temperature, I took readings with my instant read thermometer. 

For the first round, I chose 8 ounces at 160°. The temperature was actually only 129°. That’s not hot enough for tea. On subsequent rounds, done immediately after, the readings were 142°, 155°, and 156°. It never made it to 160°. 

Right after that, I selected 200°, and the actual temperature was only 178°. Then I dispensed another cup, and it went up to 184°. I also tried dispensing 200° water first thing the next morning, and it was only 145°!

So, if you want it really hot, it’s best to dump out the first cup and dispense another one or two so it can warm up to the right temperature.

On the flip side, if you just dispensed hot water, you can’t expect to be able to dispense a glass of 68° water. It needs a little time to cool down. And, it doesn’t chill the water, so you could expect the 68° setting to produce water at about room temperature.

Volume off by a bit

Next I thought I’d check to see if the amount of water being dispensed matches what it says on the display. 

In each case, the actual volume I got was one ounce more than what was expected. Not a big deal - just don’t rely on it for recipes, and especially for mixing baby formula!

Overall, a good experience

Other than those relatively minor issues, I found the NU Aqua Countertop to be easy and fun to use. Best of all, it makes the water taste clean and fresh!

What kind of maintenance will I have to do?

Besides replacing the filters when they wear out, there’s not much maintenance to do on this system.

In the user manual, the manufacturer suggests cleaning the water storage tank and drip tray once a week. That’s easy enough to do with some dishwashing liquid and water.

There are no other instructions about maintenance. I’m not so sure that’s adequate, though.

NU Aqua Countertop RO System with cover removed

Certainly, the pure water tank should be cleaned periodically since it doesn’t have a UV light to keep bacteria from growing in there. You can’t take the tank out, so I’m not sure how you’re supposed to clean it other than wiping it out.

The pure water tank has a cover you can remove, so you could get in there with a sponge or washcloth. Another idea would be to spray it with hydrogen peroxide, wait a few minutes, then wipe it with a clean cloth. Hydrogen peroxide is a good non-toxic disinfectant.

It also would be a good idea to sanitize the entire system at least once a year, but the user manual doesn't mention this.

What are the pros and cons?

NU Aqua Countertop RO

Pros and Cons

What People Like

  • Hot filtered water on demand
  • Attractive design
  • Excellent wastewater ratio
  • Water tastes great
  • No installation

Don't Like So Much

  • No continuous flow button
  • No UV light
  • Can't use during power outage
  • Pricey

Where is NU Aqua made?

NU Aqua products are manufactured in Taiwan. NU Aqua Systems is a division of Niche Webstores, Inc., located in Brea, California.

Where can I buy it?

You can purchase the NU Aqua 4-Stage Countertop RO System directly from NU Aqua Systems

Shipping is free within the continental United States, and they accept credit cards plus several e-payment methods. Sometimes they have special sale prices on their products, so it’s definitely worth checking out.

In addition, you can use coupon code MARGE5 for 5% off the NU Aqua 4-Stage Countertop RO System with Hot Water.

Click here to check the price at NU Aqua Systems.

Is there a warranty on NU Aqua?

NU Aqua offers a one year warranty on this product. This does not include the filters.

Verdict: Great choice for tea drinkers

NU Aqua Countertop Reverse Osmosis System with Hot Water

After using the NU Aqua Countertop RO in my own kitchen, I wouldn’t hesitate to recommend it.

If you’re someone who drinks a lot of hot beverages or needs purified warm water for baby formula, then you can’t beat the convenience.

The water tastes amazing, plus the wastewater ratio is impressively low. Easy setup with no installation hassle is a huge bonus, too.

It is a bit on the expensive side, so you’ll have to decide if the luxury of instant filtered hot water is worth the higher price tag.

If it is, then head over to NU Aqua and get your hands on one!

Click here to buy from NU Aqua Systems.

Remember to use code MARGE5 for 5% off!

Not sure if this is the right RO for you? Check out more great options in this post: The Absolute Best Reverse Osmosis Systems for 2023.

Alternative Brand: If you're interested in a countertop reverse osmosis filtration system without a hot water dispenser, I recommend checking out my review of the SimPure Y7P-BW RO system.

Disclaimer: I was provided with a free NU Aqua 4-Stage Countertop Reverse Osmosis System with Hot Water in return for my honest review. I have not - nor will I - receive monetary compensation from NU Aqua for this review. All opinions expressed herein are my own and not influenced by the manufacturer and/or its affiliates, in any way.

Last Updated on August 22, 2023

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