iSpring RCC7AK Under Sink Reverse Osmosis System Review

It’s hard to overlook the iSpring RCC7AK RO system since it’s among the most positive reviewed systems out there. It’s not perfect in all the ways and with this review, we’re taking a better look at it. 

iSpring water systems produce certified Reverse Osmosis units and that is supported by the Water Quality Association.

iSpring RCC7AK Under Sink Reverse Osmosis System

At a glance the iSpring RCC7AK RO system will:

  • Remove 98% of the chemicals, heavy materials, and sediments.
  • Purify up to 75 gallons on a daily basis.
  • Waste water at a rate of 3:1.

Filtration system design

The purification follows a six steps process. The first three are the main filters.

1) PP sediment filter, housed in a transparent case.

2) Carbon KDF (GAC) filter to remove larger particles.

3) Carbon block (CTO) filter to remove finer particles and chemicals.

Afterward, water goes through the fourth stage, which is the essence of any reverse osmosis system.

4) Reverse Osmosis (RO) membrane – to remove the smallest contaminants down to 0.0001 microns.

Then, the water is collected into the storage tank, almost ready for usage. RO purified water is considered among the purest there are. Usually, there are ways to add back some useful minerals and recreate the natural water taste that you get in spring water.

However, with iSpring RCC7AK, before the water is delivered to the faucet, it undergoes even more treatment.

5) Fine GAC (Carbon) filter provides final polishing for freshness.

6) An Alkaline remineralization filter adds healthy minerals and a natural pH balance, resulting in a natural water taste.

The final AK filter adds back healthy minerals including calcium and magnesium. And we do know the actual benefits of drinking remineralized water.

Water Efficiency

The iSpring RCC7AK wastes 3 gallons to produce a gallon of purified water. As usual, the amount will vary depending on your feed water pressure.

The manufacturer recommends 45 PSI – 70 PSI for the incoming waterline. 3:1 waste to water ratio is average, compared to other similar systems. The higher the pressure, the less water will be wasted. 

The iSpring RCC7AK is designed to be installed easily, on your own, and comes with everything you need, except for tools.

You’re also able to connect output lines to your ice maker, coffee maker, etc.



The faucet is among the nicest I’ve seen among other RO systems out there. Solid brass faucet with brushed nickel finish. If you manage to match it to the existing kitchen sink faucet they would complement each other nicely.


Video instructions are easy to follow and show the real installation process instead of a demonstration. I even would recommend watching then if you’re installing other RO systems based on the same design.


Tubing is color-coded in four colors. This and video instructions make it super easy to understand where and how to connect your system. Especially useful if this is your very first RO system and you’re still getting confidence in your DIY skills. It could prove a very good project indeed.


The first, sediment filter has a clear casing. This is helpful to help estimate if the filter change or a system flush is needed.



• Don’t keep it off for too long

It looks that if the RO water is unused for an extended period of time, some of it sits in the sixth stage – the Alkaline Remineralization. There it may acquire more dissolved minerals than needed, resulting in an off-taste. To prevent that just let some of the water go, for about 10 sec. and you’ll be good to go.

• Alkalinity might be off

Also related, some people claim that the remineralization module increases alkalinity above acceptable levels. If this is an issue, it’s possible to bypass it with tubing, and remineralize water afterwards.

• Alkalinity might not be there

It gets stranger still as some people claim that the pH of water delivered through the remineralization module is not alkaline enough. It might be that the iSpring company is trying to address these issues and are trying to dial in with a perfectly balanced remineralization unit.

Better installation tips


  • Variable speed drill with two bits
  • ¼” (for drilling a hole on PVC drain pipe)
  • ½” (if you need to drill a hole on a countertop for drinking faucet)
  • Adjustable wrench or 5/8” and 9/16” simple wrenches
  • Phillips head screwdriver
  • Scissors or utility knife
  • Teflon tape

Keep in mind that you’ll need space under the sink for the system dimensions of 14.5w x 6d x 18h. And a Storage Tank with a capacity of 3.2 gallons.

Pro tip. When applying Teflon tape, start with it from below on a thread and wrap clockwise three to four times. This assures that when you screw the valve on the thread, the tape stays in place. Basically, the tape wrapping needs to follow the direction of twisting motion. Otherwise, the tape might get mangled a bit, resulting in an uneven seal.

If you’ll need video instructions of how to install this iSpring RO system, here they are:

My verdict

4 out of 5.

The iSpring RCC7AK Under Sink Reverse Osmosis System is really popular. It does the job pretty well.

The whole system is backed by a 1-year money-back guarantee, a 1-year manufacturer warranty, and iSpring’s lifetime technical support provided in the USA. The maintenance of the system is simple. If you need a guide on how to wash and disinfect your RO system, I have one for you right here on my website.

However, the strange mishaps with the remineralization unit should be somehow addressed for good.
In the meantime, I give it Four out of Five. There is no doubt that if the mentioned issues will be addressed, the review could go up by one point easily making this among the best RO systems for its price.


This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

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