Chlorine-Free Pool Treatments: A Hawaii Pool Pro's Honest Guide

If there is one question I hear more than any other from East Honolulu homeowners, it is this: “Paul, can I get rid of the chlorine?” After 26 years of servicing pools across Hawaii Kai, Kahala, Diamond Head, and beyond, I completely understand why people ask. The red eyes after a family swim, the bleached swimsuits, the chemical smell that clings to your skin even after a shower — these are real frustrations. And here in Hawaii, where we swim year-round instead of just three or four months, the cumulative exposure to chlorine is significantly higher than what mainland pool owners experience.

The short answer is yes, you can dramatically reduce or nearly eliminate traditional chlorine in your pool. But the full answer — the one I wish more pool companies would give their customers — is more nuanced. Every alternative system I have worked with over the past two and a half decades has trade-offs, and what works beautifully in a shaded Kahala estate may be a poor fit for a sun-blasted pool deck in Portlock.

Let me walk you through every viable option, what I have personally seen work (and fail) in Hawaii’s unique conditions, and how to make the right choice for your family and your budget.

Why Hawaii Pool Owners Want Alternatives

Living in East Honolulu means your pool gets used differently than pools on the mainland. There is no “closing the pool for winter” here. Your family, your guests, and probably your neighbors are swimming 12 months a year. That constant use means constant chlorine exposure, and it adds up.

I have also noticed that since Hawaii passed its reef-safe sunscreen law, many of my clients have become more broadly conscious about the chemicals in and around their homes. The same families choosing mineral sunscreen to protect our coral reefs are now asking what they can do about the chemicals in their pools.

Beyond personal preference, Hawaii’s intense UV rays actually create a practical reason to explore alternatives. Our tropical sun degrades chlorine at two to three times the rate of mainland cities. That means you are buying more chlorine, adding it more frequently, and dealing with more dramatic chemical swings throughout the week. An alternative system that provides steadier sanitization can actually save you money and headaches, even before you factor in comfort.

Is Chlorine Actually Dangerous?

Before we dive into alternatives, I want to be honest with you: chlorine at proper pool levels of 1 to 3 parts per million is not inherently dangerous. Your tap water contains chlorine. The EPA considers low-level chlorine exposure safe for the general population.

What people actually react to are chloramines — the chemical byproducts that form when chlorine reacts with sweat, body oils, urine (yes, even in the best families), and sunscreen residue. Chloramines cause the “chlorine smell,” the red eyes, and the skin irritation. Ironically, a pool that smells strongly of chlorine usually does not have enough free chlorine — it has too many chloramines.

That said, there are legitimate reasons to seek alternatives beyond comfort:

• Sensitive skin conditions like eczema or psoriasis that chlorine aggravates
• Children and elderly swimmers who are in the pool daily and accumulate exposure
• Respiratory sensitivity — chloramines can trigger issues for asthma sufferers
• Pool equipment longevity — some alternatives are gentler on plaster, tile, and metal components
• Environmental consciousness — reducing chemical runoff into our island ecosystem

The Five Chlorine Alternatives at a Glance

Here is a quick comparison before we get into the details. I have included real-world cost estimates based on what I see here in Hawaii, where equipment and shipping costs tend to run 10 to 20 percent higher than mainland prices.

Saltwater Chlorine Generators

Saltwater systems are by far the most popular alternative I install across East Honolulu, and for good reason. The technology has matured significantly since the early units I worked with back in the 2000s. Modern salt chlorine generators produce a steady, consistent level of chlorine through electrolysis, which feels completely different from dumping liquid chlorine or tablets into a pool manually.

If you want a deeper comparison, I wrote a full breakdown in my post on saltwater vs. chlorine pools.

How it works: You dissolve pool-grade salt (about 3,200 ppm, which is one-tenth the salinity of ocean water) into your pool. The salt cell uses electrolysis to split salt molecules and generate pure chlorine on demand. The chlorine sanitizes the water, then reverts back to salt, and the cycle continues.

What I love about saltwater in Hawaii:

The water feels incredible — silky and soft rather than harsh. My clients in Hawaii Kai and Portlock consistently tell me their skin and eyes feel dramatically better. Because the system generates chlorine continuously rather than in peaks and valleys, chloramine formation is much lower, which eliminates most of the irritation people associate with chlorine pools.

The ongoing costs are significantly lower than traditional chlorine. You are spending $100 to $300 per year on salt instead of $400 to $900 on chlorine chemicals. Over a five-year period, the system typically pays for itself.

The Hawaii-specific concerns I tell every client about:

Salt is corrosive, and in Hawaii, we already battle salt air corrosion from the trade winds every single day. Adding more salt into the equation accelerates corrosion on metal pool fixtures, stone coping, and certain types of pool plaster. I have seen beautiful travertine decks develop salt damage around Diamond Head homes because the system was not properly maintained.

The salt cell itself needs replacement every three to seven years at a cost of $700 to $1,200. In Hawaii’s intense UV and heat, I typically see cells lasting closer to three to five years. You also need to monitor calcium hardness more carefully, as salt systems can cause scaling issues in our naturally mineral-rich water.

UV Sanitization Systems

UV sanitization has been used in municipal water treatment and medical settings for decades, and the residential pool versions have become impressively effective. I have been installing more UV systems in the past five years than in all my previous years combined, particularly for families with young children or swimmers who have skin conditions.

How it works: Water passes through a chamber containing a powerful UV-C lamp (the same germicidal wavelength used in hospitals). The UV light destroys the DNA of bacteria, viruses, parasites, and algae spores, rendering them unable to reproduce. The treated water returns to the pool effectively sterilized.

Why UV works exceptionally well in Hawaii:

Our pools run year-round, which means the UV chamber processes water continuously rather than sitting idle for months. The system destroys chloramines as water passes through, which directly addresses the irritation complaints I hear most often. I have clients in Aina Haina and Waialae Iki running UV systems who tell me their pool no longer has any chemical smell at all.

UV systems are compatible with both chlorine and saltwater pools, making them an excellent add-on rather than a full replacement. You can reduce your chlorine to as low as 0.5 ppm (compared to the standard 1 to 3 ppm) while maintaining full sanitation.

The honest limitations:

UV provides no residual sanitization. It kills everything passing through the chamber, but it does nothing for contaminants that enter the pool between filtration cycles. This is why you still need a small amount of chlorine or bromine as a residual sanitizer. I always explain this clearly to my clients because “chlorine-free” marketing around UV systems can be misleading.

The UV lamp needs replacement every 12 to 18 months at a cost of $80 to $250, and the system does increase your electricity usage. With HECO rates among the highest in the nation, that is worth factoring in — expect an additional $10 to $25 per month on your electric bill depending on the unit size.

Ozone Generators

Ozone is the most powerful oxidizer available for residential pools. It destroys contaminants approximately 3,000 times faster than chlorine and produces the clearest water I have ever seen in a pool. When a client tells me they want the absolute best water quality possible and budget is flexible, ozone is the technology I recommend exploring.

How it works: An ozone generator converts oxygen (O2) into ozone (O3) using either UV light or corona discharge. The ozone is injected into the plumbing line where it immediately begins oxidizing organic contaminants, bacteria, and algae. Its half-life in water is only about 20 minutes, so it does its work quickly and then reverts to regular oxygen.

My experience with ozone in Hawaii:

I have maintained ozone systems on several larger properties in Hawaii Loa Ridge and Kahala, and the water clarity is genuinely remarkable. One client described it as “looking like the pool is empty” because the water is so transparent. Ozone also eliminates chloramines on contact, so there is zero chemical odor.

Ozone is particularly effective in Hawaii because our warm water temperatures can accelerate bacterial growth, and ozone handles that challenge without dumping extra chemicals in. It also reduces the formation of disinfection byproducts, which is a concern for pools that get heavy daily use.

What to know before investing:

Like UV, ozone does not provide residual sanitization. You still need a small chlorine residual of 0.5 to 1.0 ppm. The equipment is also more complex than other alternatives, with more components that can fail. I recommend ozone only for homeowners who have a professional service relationship (like our pool maintenance service) to keep the system properly calibrated.

Corona discharge ozone generators are more expensive but significantly more effective than UV ozone generators. If you are going ozone, invest in the better technology. Expect $1,500 to $2,800 installed for a quality corona discharge system in Hawaii.

Bromine Sanitization

I need to be straightforward about bromine: I rarely recommend it for outdoor pools in Hawaii, and I want to explain why so you do not waste your money.

Bromine is a halogen sanitizer in the same chemical family as chlorine. It is genuinely gentler on skin and eyes, remains effective across a wider pH range (7.0 to 8.4 vs. chlorine’s narrower 7.2 to 7.6 sweet spot), and produces fewer irritating byproducts. For indoor pools and hot tubs, it is excellent.

The Hawaii problem:

Bromine degrades rapidly in direct UV light. Hawaii’s UV index regularly exceeds 11, which is classified as “extreme” by the World Health Organization. In my testing, bromine levels in an uncovered outdoor pool here in East Honolulu can drop from 3 ppm to near zero in just four to six hours of peak sun exposure. That means you are constantly adding bromine — and at $30 to $50 per month (1.5 to 2 times the cost of chlorine), the expense adds up quickly without delivering reliable sanitization.

I have also found that bromine leaves a distinctive odor that some people find more objectionable than chlorine, particularly in warm outdoor settings. When it reacts with organic matter in the heat, the smell can be unpleasant.

Where bromine does make sense: If you have a covered lanai pool that gets minimal direct sun, or an indoor pool (which some Portlock and Kahala estates have), bromine can be a comfortable and effective choice.

Copper Ionization

Copper ionization is an interesting technology that I have seen gain popularity over the past decade, particularly among pool owners battling persistent algae problems. Hawaii’s warm temperatures and year-round growing conditions make algae an ongoing challenge, and copper ions are exceptionally effective at preventing it.

How it works: An electronic ionizer (or solar-powered unit) releases microscopic copper ions into the pool water. These ions disrupt the cellular processes of bacteria and algae, killing them over time. Some systems also release silver ions for additional bacterial control.

Where copper ionization shines in Hawaii:

Black algae is the bane of many Hawaii pool owners. It embeds itself in plaster and is nearly impossible to eliminate with chlorine alone. Copper ions penetrate the protective layers of black algae in ways that chlorine cannot. I have recommended ionization systems to clients in Kuliouou and Kalama Valley specifically for this reason, and the results have been impressive.

The long-term chemical savings are real. My clients using ionizers typically spend $150 to $400 per year on pool chemicals compared to $400 to $900 without the system. Over five years, that savings more than covers the initial equipment cost.

The critical warning I give every client:

Copper levels must be carefully monitored. If copper concentration exceeds 0.3 ppm, it can cause blue-green staining on pool plaster, tile grout, and even blonde hair. I have had to help several homeowners remediate copper staining because their previous service company was not monitoring levels closely enough. This is not a “set it and forget it” system — it requires consistent professional oversight.

Additionally, copper ionization works slowly. It is a supplemental system, not a standalone sanitizer. You still need a small amount of chlorine (0.5 to 1.0 ppm) for immediate sanitization of new contaminants entering the pool.

Combination Systems: The Best of Both Worlds

After two and a half decades of working with every system on this list, my strongest recommendation for most East Honolulu pool owners is a combination approach. No single alternative completely eliminates the need for some form of chlorine, but combining technologies gets you as close to chlorine-free as current technology allows.

Hawaii-Specific Considerations

No matter which alternative you choose, there are factors unique to Hawaii that will affect your system’s performance. These are the things I discuss with every client during a consultation, and they are often the difference between a system that works beautifully and one that disappoints.

My Recommendations by Situation

After working on hundreds of pools across every neighborhood in East Honolulu, here is how I guide my clients based on their specific situations:

How Much Chlorine Can You Actually Eliminate?

Let me give you realistic expectations based on what I see in the field, not manufacturer marketing claims:

*Saltwater systems still produce chlorine — just a gentler, steadier form through electrolysis. The total chlorine level is similar, but the swimming experience is dramatically better because chloramine formation is minimized.

Frequently Asked Questions