8 Points to consider before buying an under counter RO system

Gabe Ergler |

Why we have under counter ROs?

RO's (reverse osmosis) are often installed to improve drinking and cooking water when the water in the kitchen is not satisfactorily treated by other means.

Even if your house has a treatment system it may also have a soft water plumbing loop that prevents whole house treatments from sending treated water to the kitchen and outdoor faucets. The reason for the soft water loop is to give you a place to get water that does not contain elevated levels of salt produced during the softening process. Water produced by a salt-based softener can't be used to water plants, gardens and lawns, it changes the way water and coffee and tea tastes and it may need to be avoided in your diet.

It’s important to understand that both RO and new more advanced systems are designed to help you get the same thing: better water in your home. 

But there are a few differences in how each system does that. And, perhaps most importantly, one of these systems (hint: it’s the ICS PolyHalt® softener ICS-TPU) is not only much easier to use and install, but has a dramatically smaller environmental footprint. 

The ICS-TPU is a POU (Point of Use) 3 stage treatment system. The first treatment is filtration with activated carbon to remove chlorine, improve taste, and reduce VOCs. Second is a salt free water softener and finally water is conditioned to protect plumbing and appliances from low pH aggressive water. 

8 Points to consider before buying (or replacing) an under counter RO system

1. Treatment flow rate - Is it enough?

This has always been a limitation of an RO system. They have a limit on how much water they can treat stated in terms of GPD (gallons per day) they produce. Most will produce somewhere around 25-50 GPD or 2-4 gallons per hour. Compare this to our ICS-TPU that treats 5 gallons per minute or 300 gallons per hour. 

2. Where do you want treated water

Do you want to treat water going to one faucet or everywhere in your kitchen? RO treated water is delivered through it's own separate faucet. This is fine if you do not want to treat water going to your kitchen sink, dishwasher, ice maker etc. Having it's own faucet also means drilling a hole through your sink or counter top is required in order to mount the faucet. Having a hole drilled can be very costly in materials like granite, much more than the cost of the RO system.

Compare this with the ICS-TPU where all the water used in the kitchen is treated and no separate faucet is required.

3. Environmental impacts

When RO systems were being developed, most of us were not concerned about the impacts on the environment. Basically we didn't think twice about wasting fresh water down the drain.

RO systems have a certain amount of waste built into them, they are around 25% efficient. This means for every gallon of water that goes through the RO only 25%, or 1 quart, is usable water and the other 75% is waste and goes down the drain.

ICS-TPU systems are 100% efficient. That means whether you use a lot or little, 100% of your water passes through for consumption with no waste.

4. How much space do you have under your counter

An RO system is big and often consumes 1/2 or more of the space under the kitchen sink. If you’re like most people, your under-sink storage is premium and an RO system takes a bunch of it leaving little for cleaners, garbage cans etc.

Contrast that with the the ICS-TPU, It’s a single housing cartridge filter with no tank, drain line, extra hoses or a faucet. It mounts to the wall, out of the way, freeing up ‘floor’ space.

5. Are you OK with low pH water?

Most don't know RO systems product low pH water. That's right ROs make acidic water. This is something to be aware of as low pH water will dissolve metallic surfaces of items such as plumbing, valves, fixtures and appliances. 

On the other hand the ICS-TPU does not make low pH water and in fact it contains properties that protect metallic surfaces.

6. Is an RO too noisy?

Remember when we learned that ROs are only 25% efficient? Well, all that waste water goes through a tube to the sink drain and more often than not when the RO is making clean water you can hear the waste water going down the drain.

The ICS-TPU doesn't produce any waste and is completely silent.

7. Are pharmaceuticals a concern?

Some will insist an RO is required to remove pharmaceuticals from the water insinuating nothing else will. In fact, both RO and the ICS-TPU activated carbon filter remove some pharmaceuticals.1

8. What to do with the faucet hole

If you replace an existing RO you won't need the separate counter top faucet and will have to decide what to do with the hole the faucet piping went through.

Here are 3 ideas for for what to do with the faucet hole.

  1. Install a liquid soap dispenser
  2. Install a push button switch for your garbage disposal
  3. Install a faucet hole cover


Nowadays, considering advances in salt free water treatment, large, complicated and expensive under counter RO systems with limited flow rates of low pH product water just aren't required in most situations.

A smaller salt free ICS-TPU that treats all the kitchen water may be a better option.


1. Drugs in our Drinking Water?By Kathleen Doheny: WebMD