What Is the Downside of Reverse Osmosis Water?

The Truth Nobody Wants to Say… Because They’re Too Busy Selling You a System

What Is the Downside of Reverse Osmosis Water? Let’s get one thing straight:
Reverse osmosis isn’t the problem.
The problem is what’s left out of the conversation.

Most people talking about water filtration have one goal: to close the deal.
At McCowin Water, we’ve spent 50+ years walking into homes after those deals go bad.

We’ve seen reverse osmosis units that stripped the minerals and left the acidity.
We’ve seen “bargain” filters that created $30,000 copper damage in six months.
We’ve seen homeowners told they were “protected” while quietly drinking water contaminated with fluoride, PFAS, lead, and chromium 6.

So let’s stop dancing around it.
This is the truth about the downside of reverse osmosis water; without spin, sales pressure, or gimmicks.

Just facts.

What Reverse Osmosis Actually Does

Reverse osmosis is a point-of-use purification system that forces water through a semi-permeable membrane. That membrane is tight enough to block:

• Arsenic
• Barium
• Chromium 6
• Lead
• Fluoride
• PFAS
• Nitrates
• Copper
• Pharmaceuticals
• Radium 226 & 228

Source: NSF/ANSI 58 certification standards

It works. It’s one of the only technologies that can handle these chemical signatures reliably.

But that performance has consequences, if the system isn’t handled properly.

Here’s What Most People Don’t Know

1. What Is the Downside of Reverse Osmosis Water? Reverse Osmosis Removes the Good Along With the Bad

That membrane is unforgiving. It doesn’t just take out the bad actors, it strips everything:

• Calcium
• Magnesium
• Sodium
• Trace minerals

What you’re left with is demineralized water; a blank slate.

For most people, that isn’t harmful. But over time, drinking water with zero mineral content can:

• Flatten the taste
• Reduce hydration efficiency
• Interfere with electrolyte balance in those with poor diets or kidney sensitivity

And in certain conditions, that mineral-free water becomes chemically aggressive, meaning it starts pulling minerals from pipes, fixtures, or anything else it touches.

2. What Is the Downside of Reverse Osmosis Water? It Can Become Acidic… and That Has Real Impact

When water is demineralized, it often drops below a neutral pH.

Acidic water:

• Wears down copper pipes
• Picks up metal residues
• Causes pitting in plumbing
• Eats through faucet components
• Leaves you with water that’s “clean,” but not stable

This is where most RO installs fail. Not because of the membrane, but because no one considered the chemistry of the house it was installed in.

3. What Is the Downside of Reverse Osmosis Water? It Wastes Water, Unless You Know What You’re Doing

Every gallon of purified water produced by reverse osmosis creates reject water, also called “wastewater.”

Lower-end units can waste 3-5 gallons for every 1 gallon purified.
Higher-end systems are now getting that down to a 1:1 or even 1:0.5 ratio.

But unless the system is pressure-balanced, flow-regulated, and correctly staged, it becomes a hidden water bill no one tells you about.

We’ve seen installs in Orange County homes where a single under-sink unit added 17% to the water bill.

Not because it was broken.
Because it was installed by someone who didn’t measure, monitor, or calibrate.

4. What Is the Downside of Reverse Osmosis Water? It Needs Real Maintenance, Not Just Filter Swaps

The RO membrane itself is delicate.
If chlorine reaches it… game over.

If sediment isn’t pre-filtered… flow rate crashes.

If filters aren’t changed on time… bacteria can colonize the system and backflow into the tank.

RO systems require staging:

• Sediment filtration
• Chlorine removal
• Membrane protection
• Post-carbon polishing
• Optional remineralization

Miss a step? You don’t get RO. You get trouble.

So… Is Reverse Osmosis Bad?

No.
But incomplete reverse osmosis is worse than no filtration at all.

When installed with proper flow balancing, pH correction, and intelligent staging…
When chosen for the right water chemistry and system goals…
When maintained with clarity and not ignored after install…

Reverse osmosis becomes one of the most effective, efficient, and protective systems available to modern households.

But here’s the hard truth most won’t say:

A reverse osmosis system installed without accountability is just a blindfold with a faucet attached.

The Downside Isn’t in the System. It’s in the Silence.

We’ve spent decades watching people get sold a system,
But not a solution.

And the cost always comes later.

• Leaky fittings
• Bitter taste
• Rising water bills
• Slab leaks
• Mold growth from unflushed tanks
• Medical confusion when a “clean” system left contaminants behind

You won’t find this on a box at your favorite big box store.
You won’t hear it from an installer who’s gone after the invoice is signed.
But we see it every week.

And it’s why we don’t install one-size-fits-all anything.

What Makes Reverse Osmosis Work, Without Downsides?

Here’s the configuration that eliminates all major issues:

1. Pre-Sediment Filter (5 micron)
   Catches sand, rust, and grit.
2. Chlorine/GAC Pre-Filter
   Protects the membrane from chemical burnout.
3. High-Integrity RO Membrane (50 GPD or greater)
   Calibrated to pressure and water source.
4. Post-Carbon Polishing Filter
   Restores clarity and flavor.
5. Remineralization Cartridge (Optional)
   Returns pH to neutral or slightly alkaline.
6. Smart Drain Logic
   Reduces wastewater and protects plumbing.
7. Quarter-Turn Twist-Off Filter Design
   Simplifies maintenance. No tools. No contamination.

The system doesn’t need to be overhyped. It just needs to be complete.

In Closing: Ask This Before You Ever Install an RO System

• Was your water pressure tested?
• Was your TDS measured?
• Do you know your chlorine levels?
• Will the unit be staged with proper sediment and carbon filters?
• Is the membrane certified to NSF/ANSI 58?
• Will the system include pH correction or remineralization?
• Is the waste ratio documented and optimized?
• Who will service the system in a year?
• Do they know your house?
• Do they have a name to protect?

If those questions aren’t answered,
Then it’s not just about what the system takes out.

It’s what the installer leaves behind.

We Don’t Sell Fear. We Don’t Sell Hype.

We Deal in Water.

If the system is right, it’s right.
If not, we’ll tell you.
Because the cost of doing it wrong is too high.

And the people who trust us already know…

You don’t cut corners on the one thing your entire family puts in their body every single day.

• Call if you want facts.
• Book if you want clarity.
• Test if you want to stop guessing.

We’ll show you the real story.
And we’ll earn your trust… whether you choose us or not.

Because that’s what clean water is supposed to feel like:

Clear. Honest. And impossible to ignore.

Call us at (949) 569-5736 or schedule your free water test today.

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Call us at (949) 569-5736 or schedule your free water test today.