The question I hear most from East Honolulu homeowners is “Paul, can I get rid of the chlorine?” I get why people ask. Red eyes after a family swim, bleached swimsuits, that chemical smell that hangs on your skin after a shower. And in Hawaii we swim year-round instead of three or four months, so your family soaks up a lot more chlorine than a mainland family does.
The short answer is yes, you can cut traditional chlorine way down, close to nothing. The longer answer is that every alternative I’ve worked with since 2000 has trade-offs, and what works well in a shaded Kahala backyard may be a poor fit for a sun-baked deck in Portlock.
Below is each option that’s worth considering, what I’ve seen work and fail in Hawaii, and how to pick the right one for your family and budget.
- Why Hawaii Pool Owners Want Alternatives
- Is Chlorine Actually Dangerous?
- The Five Chlorine Alternatives
- Saltwater Chlorine Generators
- UV Sanitization Systems
- Ozone Generators
- Bromine Sanitization
- Copper Ionization
- Combination Systems
- Hawaii-Specific Considerations
- My Recommendations by Situation
- Frequently Asked Questions
Why Hawaii Pool Owners Want Alternatives
Nobody closes the pool for winter here. Your family, your guests, and probably your neighbors are swimming 12 months a year. That means 12 months of chlorine exposure, and it adds up.
Since Hawaii passed its reef-safe sunscreen law, I’ve also noticed more of my clients paying attention to the chemicals around their homes in general. The same families buying mineral sunscreen to protect the reef are asking what they can do about the chemicals in their pools.
There’s also a practical reason to look at alternatives. Our tropical sun breaks down chlorine two to three times faster than it does in mainland cities. You buy more chlorine, add it more often, and ride bigger chemical swings through the week. A system that keeps sanitizing steadily can save you money and hassle before you even count the comfort.
Is Chlorine Actually Dangerous?
At normal pool levels of 1 to 3 parts per million, chlorine isn’t dangerous. Your tap water has chlorine in it, and the EPA considers low-level exposure safe for the general population.
What people react to are chloramines, the byproducts that form when chlorine reacts with sweat, body oils, urine (yes, even in the best families), and sunscreen. Chloramines cause the “chlorine smell,” the red eyes, and the itchy skin. A pool that smells strongly of chlorine usually doesn’t have enough free chlorine. It has too many chloramines.
Chloramines are the real problem. They form when chlorine reacts with sweat, body oils, and sunscreen, and they cause most of the irritation people blame on chlorine. A lot of alternative systems work by cutting down chloramines rather than removing chlorine entirely. Knowing that will help you spend your money in the right place.
Comfort aside, there are solid reasons to look for alternatives:
- Sensitive skin conditions like eczema or psoriasis that chlorine aggravates
- Kids and older swimmers who are in the pool every day and build up exposure
- Asthma and other breathing issues that chloramines can set off
- Longer-lasting equipment, since some alternatives are easier on plaster, tile, and metal parts
- Less chemical runoff into our island’s streams and reef
The Five Chlorine Alternatives at a Glance
Here’s a quick comparison before the details. The costs are what I see here in Hawaii, where equipment and shipping tend to run 10 to 20 percent above mainland prices.
Saltwater Generator
Turns dissolved salt into chlorine through electrolysis. Makes chlorine steadily, so the water feels gentler and you're not dosing chemicals by hand.
UV Sanitizer
An ultraviolet light chamber kills bacteria, viruses, and algae as water passes through. Can cut chlorine use by up to 90%.
Ozone Generator
Converts oxygen to ozone (O3), a strong oxidizer. Breaks down contaminants about 3,000 times faster than chlorine and gives the clearest water of any option here.
Bromine
A sanitizer in the same family as chlorine but easier on skin and eyes. Works across a wider pH range, but the sun burns it off fast.
Copper Ionizer
Releases copper (and sometimes silver) ions that kill bacteria and keep algae from taking hold. Works well against the stubborn black algae we see a lot of in Hawaii.
Saltwater Chlorine Generators
Saltwater is the alternative I install most across East Honolulu, and there’s good reason for it. The technology has come a long way since the early units I worked on in the 2000s. A modern salt chlorine generator makes a steady level of chlorine through electrolysis, which feels completely different from pouring in liquid chlorine or tablets by hand.
For the full comparison, see my post on saltwater vs. chlorine pools.
How it works: You dissolve pool-grade salt into the water (about 3,200 ppm, roughly a tenth as salty as the ocean). The salt cell uses electrolysis to split the salt and make chlorine as the pool needs it. The chlorine sanitizes the water, turns back into salt, and the cycle repeats.
What I like about saltwater in Hawaii:
The water feels soft instead of harsh. My clients in Hawaii Kai and Portlock tell me their skin and eyes feel much better. Because the system makes chlorine continuously instead of in spikes and dips, far fewer chloramines form, and that gets rid of most of the irritation people associate with chlorine pools.
It’s also cheaper to run. You spend $100 to $300 a year on salt instead of $400 to $900 on chlorine. Over five years, the system usually pays for itself.
The Hawaii concerns I bring up with every client:
Salt is corrosive, and we already fight salt air off the ocean every day. Adding salt to the water speeds up corrosion on metal fixtures, stone coping, and some types of plaster. I’ve seen good travertine decks around Diamond Head homes get salt damage because nobody maintained the system properly.
The salt cell needs replacing every three to seven years at $700 to $1,200. With our heat and UV, I usually see cells last closer to three to five years. You also have to watch calcium hardness more closely, because salt systems can scale up in our mineral-heavy water.
Pros and Costs
Pros and Costs
UV Sanitization Systems
Cities and hospitals have used UV to treat water for decades, and the home pool versions work well now. I’ve been putting in more UV systems the last few years, mostly for families with young kids or swimmers with skin conditions.
How it works: Water runs through a chamber with a UV-C lamp, the same germ-killing wavelength hospitals use. The light wrecks the DNA of bacteria, viruses, parasites, and algae spores so they can’t reproduce. The water goes back to the pool clean.
Why UV fits Hawaii pools:
Our pools run all year, so the UV chamber is treating water every day instead of sitting idle for months. It also breaks down chloramines as the water passes through, which goes straight at the irritation complaints I hear most. Clients in Aina Haina and Waialae Iki with UV systems tell me their pools don’t smell like chemicals at all anymore.
UV works with both chlorine and saltwater pools, so think of it as an add-on rather than a replacement. You can run chlorine as low as 0.5 ppm (instead of the usual 1 to 3 ppm) and still keep the pool properly sanitized.
The limitations:
UV leaves nothing behind in the water. It kills whatever passes through the chamber and does nothing about what lands in the pool between cycles. That’s why you still need a little chlorine or bromine in the water. I make a point of explaining this, because a lot of “chlorine-free” UV marketing is misleading.
The lamp needs replacing every 12 to 18 months at $80 to $250, and the system uses electricity. With HECO rates among the highest in the country, figure an extra $10 to $25 a month on your electric bill depending on the unit size.
Ozone Generators
Ozone is the strongest oxidizer you can put on a home pool. It breaks down contaminants about 3,000 times faster than chlorine, and it gives the clearest water I’ve ever seen in a pool. When a client tells me they want the best water possible and budget isn’t the main concern, ozone is where I point them.
How it works: An ozone generator turns oxygen (O2) into ozone (O3) using either UV light or corona discharge. The ozone gets injected into the plumbing line, where it goes right to work on organic contaminants, bacteria, and algae. It only lasts about 20 minutes in water before turning back into regular oxygen.
My experience with ozone in Hawaii:
I’ve maintained ozone systems on several larger properties in Hawaii Loa Ridge and Kahala, and the clarity is remarkable. One client said it looks like the pool is empty. Ozone also destroys chloramines on contact, so there’s no chemical smell.
It’s a good match for Hawaii because warm water grows bacteria faster, and ozone handles that without adding more chemicals. It also cuts down on disinfection byproducts, which matters for pools that see heavy use every day.
What to know before you buy:
Like UV, ozone leaves nothing behind in the water, so you still need a small chlorine residual of 0.5 to 1.0 ppm. The equipment is also more complicated than the other options, with more parts that can fail. I only recommend ozone for homeowners who have regular professional service (like our pool maintenance service) to keep it calibrated.
Corona discharge generators cost more than UV-type ozone generators and work a lot better. If you’re going with ozone, buy the better one. Expect $1,500 to $2,800 installed for a good corona discharge system in Hawaii.
Bromine Sanitization
I rarely recommend bromine for outdoor pools in Hawaii, and I want to explain why so you don’t waste money on it.
Bromine is in the same chemical family as chlorine. It’s easier on skin and eyes, works across a wider pH range (7.0 to 8.4, compared with chlorine’s 7.2 to 7.6 sweet spot), and makes fewer irritating byproducts. For indoor pools and hot tubs, it’s excellent.
The Hawaii problem:
Sunlight breaks bromine down fast. Our UV index regularly goes past 11, which the World Health Organization classifies as “extreme.” In an uncovered East Honolulu pool, a strong afternoon of sun can burn bromine down to almost nothing. So you’re adding it constantly, at $30 to $50 a month (1.5 to 2 times the cost of chlorine), and still not getting dependable sanitizing.
Bromine also has its own smell that some people like even less than chlorine, especially outdoors in the heat when it’s reacting with sweat and sunscreen.
My take on bromine in Hawaii: Save it for your hot tub or an enclosed indoor pool. On an outdoor pool in East Honolulu sun, bromine is throwing money away. You'll spend more, add chemicals more often, and still not get reliable sanitizing during the hottest part of the day. Chlorine with a UV or ozone add-on is a much better use of your money.
Where bromine does make sense: a covered lanai pool that gets very little direct sun, or an indoor pool (a few Portlock and Kahala homes have them).
Copper Ionization
Copper ionization has picked up a following over the last decade, mostly among pool owners fighting algae that keeps coming back. Our warm water and year-round growing season make algae a constant battle, and copper ions are very good at keeping it away.
How it works: An electronic or solar-powered ionizer releases tiny copper ions into the water. The ions disrupt how bacteria and algae cells work and kill them over time. Some systems add silver ions for extra bacteria control.
Where copper ionization earns its keep in Hawaii:
Black algae is a headache for a lot of Hawaii pool owners. It roots into the plaster and is close to impossible to kill with chlorine alone. Copper ions get through black algae’s protective layers where chlorine can’t. I’ve recommended ionizers to clients in Kuliouou and Kalama Valley for exactly this reason, and they’ve worked well.
The chemical savings are real. Pools with ionizers typically run $150 to $400 a year in chemicals, compared with $400 to $900 without. Over five years, that more than covers the equipment.
The warning I give every client:
Someone has to watch copper levels closely. Above 0.3 ppm, copper can leave blue-green stains on plaster and grout, and even turn blonde hair green. I’ve helped several homeowners clean up copper stains because their previous service company wasn’t keeping an eye on the levels. You can’t set this one and forget it. It needs regular professional checks.
Copper ionization also works slowly. It’s a supplement, not a standalone sanitizer. You still need a small amount of chlorine (0.5 to 1.0 ppm) to deal with new contaminants as they come in.
Combination Systems
After working with every system on this list, what I recommend for most East Honolulu pools is a combination. No single alternative gets rid of chlorine completely, but pairing two of them gets you about as close to chlorine-free as today’s equipment allows.
Saltwater + UV
The combo I recommend most. The salt cell makes gentle, steady chlorine, and the UV chamber destroys chloramines and germs. You end up with soft water and almost no chemical smell. Total cost: $2,000-$4,500.
Ozone + Low Chlorine
The top-end option for water clarity. Ozone does most of the work and a small chlorine residual covers what it misses. Best for larger pools and bigger budgets. Total cost: $2,500-$5,000.
Ionizer + Salt System
A strong pick for algae-prone pools. Copper ions keep algae away long term while the salt cell handles daily sanitizing. Cuts chemical use a lot overall. Total cost: $2,200-$4,500.
UV + Ozone + Minimal Chlorine
The closest you can get to chlorine-free. UV and ozone handle almost all the sanitizing, and you only need a 0.3-0.5 ppm chlorine residual. Total cost: $2,800-$5,500.
Hawaii-Specific Considerations
Whatever you pick, a few things about Hawaii will affect how it performs. I go over these with every client, and they often decide whether a system works well or disappoints.
Hawaii has the highest electricity rates in the country (around $0.35-$0.45/kWh). UV and ozone systems add $10-$30 a month to your electric bill, so count that in your comparison. A variable speed pump can make up some of it.
The trade winds already carry salt mist that eats at pool equipment. A saltwater system adds salt on the inside too. Buy marine-grade equipment and rinse metal fixtures regularly.
Our UV index stays extreme all year and burns off both chlorine and bromine faster. Systems that lean less on chemicals sitting in the water (UV, ozone) help the most here.
Equipment in Hawaii usually costs 10-20% more than on the mainland because of shipping. Budget for it, and buy from suppliers with local stock when you can.
Our pool water rarely drops below 75°F, so bacteria and algae grow faster all year. Whatever system you pick has to keep up with that.
My Recommendations by Situation
Here’s how I steer clients across East Honolulu, depending on their situation:
Go with a saltwater system plus a UV add-on. The salt cell keeps chlorine steady and gentle, without the spikes that cause irritation, and the UV chamber breaks down chloramines as they form. Red eyes and itchy skin mostly go away. This is what I recommend to most of my residential clients in Hawaii Kai and Aina Haina.
Put in an ozone system with a small chlorine backup. Nothing beats the clarity, there's no chemical smell, and it keeps up with heavy use from parties and events. Pair it with a variable speed pump to keep the electric bill in check.
Start with a copper ionizer alongside your current chlorine (or a salt system). The copper goes after the algae while the regular sanitizer handles bacteria. I've seen this combination end algae problems that years of shocking and scrubbing couldn't fix.
A saltwater system by itself gives you the best return. The upfront cost is moderate, the chemical savings are real, and you'll feel the difference in the water right away. You can add UV or ozone later when the budget allows.
UV plus ozone, with chlorine as low as you can safely run it (0.3-0.5 ppm). That keeps chemical exposure to a minimum and still keeps the water safe. Several of my clients whose dermatologists told them to cut chlorine exposure have done well with this setup.
How Much Chlorine Can You Actually Eliminate?
Here’s what I see in the field, which is usually less than the manufacturer’s brochure promises:
*Saltwater systems still make chlorine, just in a steadier, gentler way through electrolysis. The total chlorine level is about the same, but swimming feels much better because far fewer chloramines form.
Frequently Asked Questions
Can I completely eliminate chlorine from my pool?
Not with the home pool equipment available today. Every alternative system I've installed still needs a small residual of chlorine or bromine (usually 0.3-1.0 ppm) to handle what gets into the pool between filtration cycles. At those levels, though, you won't smell it, feel it on your skin, or get red eyes. The best combination systems cut chlorine by 90-95%, which is as close to chlorine-free as you can safely get.
Are saltwater pools actually chlorine-free?
No, and it's one of the most common misunderstandings in the pool business. Saltwater pools make chlorine through electrolysis. They just make it in a gentler way than tablets or liquid chlorine. The chlorine level in a salt pool is usually the same 1-3 ppm as a traditional pool. The difference is consistency: the salt cell makes chlorine steadily all day instead of in big doses that spike and drop, so fewer chloramines form and swimming is a lot more comfortable. My saltwater vs. chlorine comparison goes into more detail.
Which alternative system costs the least to run in Hawaii?
A saltwater system has the lowest operating cost over time. Salt runs $100-$300 a year, compared with $400-$900 for chlorine. The cell replacement every 3-5 years adds some cost, but you still come out well ahead. Copper ionizers also save on chemicals, but once you count electrode replacement they cost a little more. UV and ozone save on chemicals too, though their electricity use adds up at HECO's rates. If you want the numbers for your own pool, I'm happy to run them during a consultation.
Will salt damage my pool plaster or equipment?
It can if nobody maintains the system. Salt at pool levels (3,200 ppm) is fairly mild, but over years it can wear down certain plaster types faster, corrode metal fixtures, and damage natural stone coping. In Hawaii, where salt air already takes a toll on everything, that's a real concern. Monitoring salt levels, keeping pH balanced, and using sacrificial zinc anodes to protect metal parts will prevent most salt damage. I cover plaster care in my post on making pool plaster last longer.
How do I decide which system is right for my pool?
It comes down to what you care about most (comfort, cost, clarity, how much upkeep you want), your pool's conditions (sun, size, current equipment), and your budget. I'm a Certified Pool Operator and I've installed all of these systems across East Honolulu, so the best first step is a consultation where I look at your pool, hear what you want, and give you a specific recommendation. There's no single right answer for every pool. This guide is here so you can walk into that conversation knowing the options.
Can I convert my existing chlorine pool to an alternative system?
Yes. Every system in this guide can be added to an existing chlorine pool. Salt conversions are the simplest: we install the salt cell, add salt to the water, and the pool is ready within 24-48 hours. UV and ozone systems need some plumbing changes to fit the treatment chamber, but that's usually a one-day job. What matters most is that your current pump and filter are compatible and in good shape. Our salt system installation service and equipment repair service handle these conversions regularly.
Ready to Explore Chlorine Alternatives for Your Pool?
I've installed and maintained every system in this guide on homes in Hawaii Kai, Kahala, Diamond Head, and the rest of East Honolulu. Let me look at your pool and tell you which option fits your family, your budget, and our conditions. My father Jim founded Koko Head Pool Service in 1995, and I've been servicing pools with the company since 2000.
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