6 Ways How to Keep a Pool Clean Without Chlorine

Chlorine is cheap, easy to use, and great for disinfecting your pool. If you misuse chlorine, chloramines and trihalomethanes can harm your health, which is why many people try to clean the pool without chlorine. But what does pool maintenance look like without chlorine, and which means or systems would be an alternative to chlorine?

A salt electrolysis device or an ozone generator combined with an activated carbon filter is often used for chlorine-free pool cleaning. These devices are associated with increased costs. Disinfectants such as active oxygen, Bromine, or Biguanide are suitable as inexpensive alternatives.

This article will teach how to disinfect your pool without chlorine, which systems make sense in the long term, and what you should pay attention to when maintaining your pool water.

Advantages and disadvantages of chlorine in the pool

Chlorine belongs to the group of halogens and is the most common disinfectant in private swimming pools.

Pool maintenance with chlorine has some advantages, but it also has disadvantages to your health.

Before you decide to clean your pool completely without chlorine in the future, you should first know all the advantages and disadvantages of chlorine and then decide how the water in your pool should be disinfected.

Advantages of chlorine in your pool:

  • Efficiency: The oxidizing power of chlorine is relatively high and is well suited for water maintenance – germs and bacteria are killed much faster than with other disinfectants.
  • Low costs: The chlorine available from pool retailers is relatively cheap and available as chlorine tablets, liquid chlorine, and chlorine granulate.
  • Areas of application: The chlorine is used for the ongoing disinfection of your pool but is also suited for a pool shock.
  • Heat-resistant: Chlorine remains effective even when the water temperature in your pool is higher than 86 °F (30 °C), while the dose has to be increased with other agents such as biguanide or bromine.

You see, chlorine has its advantages. It is only important that the chlorine is used correctly in your pool.

You can learn more about the use of chlorine in the linked article. To do this, follow the link.

Disadvantages of chlorine in pool water:

  • Susceptible to UV rays: The chlorine breaks down quickly under the influence of UV rays from the sun and loses its effect unless a chlorine stabilizer is also added to it.
  • By-products: If chlorine is mixed with organic substances such as sweat, urine, etc., chloramines and trihalomethanes are formed. These by-products are responsible for the typical chlorine smell and can even lead to cancer.
  • Allergies: Many people are allergic to chlorine, causing red skin and irritation of the respiratory tract. In the worst case, chloracne or the involvement of the central nervous system can occur if chlorine is used without protective equipment.
  • Storage: Free-standing metal parts can rust when chlorine is stored. In addition, the smell is perceived by many as unpleasant.

The disadvantages of chlorine sound frightening, but the by-products are created if the dosage in your swimming pool is incorrect.

But don’t worry. A pool shock can eliminate these by-products.

Tip: Avoid any direct skin contact with chlorine and always use the chlorine in the pool with protective equipment – gloves, a breathing mask, and protective goggles.

Alternative pool maintenance without chlorine

Have you decided to run your pool without chlorine?

Congratulations, this is a good decision that you will not regret.

But which agents are suitable as chlorine alternatives, and how to disinfect your pool with the most modern technology for water treatment in private pools?

These are the six best alternatives how to keep a pool clean without chlorine:

  1. Active oxygen granules as a skin-friendly alternative.
  2. Disinfection with the saltwater electrolysis process.
  3. Biguanide (also known as PHMB – polymer hexamethylene biguanide).
  4. An ozone-broom combination.
  5. UV light and bromine.
  6. Pool ionization for disinfecting the pool.

In the individual sub-chapters, you will find a detailed description of the advantages and disadvantages of each alternative for chlorine.

Read more about this in the text.

1. Active oxygen in the pool as a chlorine alternative

Pool maintenance with active oxygen (hydrogen peroxide) is one of the gentlest methods of keeping a pool and whirlpool clean. This chemical is available from pool retailers as liquid or granulate.

An application of active oxygen is carried out either manually or with the help of dosing systems.

Your pool must occasionally be shocked with active oxygen to combat algae. In addition to the active oxygen, you should also use an algaecide in your swimming pool.

In the beginning, it was a problem in the private sector to measure the active oxygen in the water.

However, this was made more manageable by appropriate water testers.

Using active oxygen for pool maintenance is gentle on bathers, but it is significantly more expensive in the long term than using chlorine.

Estimated, you need 1 gallon per week of active oxygen per 50 m³ of pool water.

If you pay an average of 25 $ per gallon, that’s 100 $ per month – on hot days, the dose has to be increased, which of course, increases the costs.

Now the question arises: Active oxygen or chlorine?

Due to the higher costs, only an application in your hot tub is recommended, as the costs are still within reasonable limits.

But if you have the budget, then active oxygen is a wonderful alternative to chlorine for disinfecting your swimming pool.

Tip: If you switch from chlorine to active oxygen, the chlorine must first be completely removed from your pool. Otherwise, the effect will be canceled out.

2. Saltwater electrolysis instead of pure chlorine

Of all the alternatives for chlorine, saltwater electrolysis is the best method to disinfect your swimming pool – the high level of bathing comfort and environmental compatibility speak for this.

All you need is a high-quality salt electrolysis system and some salt (sodium chloride).

The system should be able to automatically reverse the polarity of the electrodes (change between + and – pool).

This is important to prevent soiling and limescale deposits.

But how exactly does the disinfection of the pool with the salt electrolysis process work?

In easy terms: The breakdown of the salt creates free oxygen that attacks bacteria and algae. In addition, free chlorine is formed that permanently disinfects the pool.

Did you say chlorine is formed? But we don’t want chlorine!

Yes, you’ve read that correctly. The system generates FREE CHLORINE for disinfecting your swimming pool.

How can salt electrolysis be an alternative to the traditional chlorine in my pool?

Although chlorine is used here, many pool owners report positive experiences who have switched from conventional chlorine to salt electrolysis.

The free chlorine is present in much smaller quantities, contains no additives, and breaks down quickly.

Once the system has been installed, around 150 kg of salt is required for every 10 m³ of pool water – The concentration of the salt should be 0.4%.

The systems for salt electrolysis are not always the cheapest, but after two years at the latest, the costs for the system will have amortized again.

It would be best to accept the extra investment for the advantages.

Tip: The salt electrolysis is suitable for all pool shapes, only with steel pools extra precautions such as galvanized weld seams are necessary so that there is no formation of rust.

Ideally, the sand in your sand filter system should be changed before switching to the pool salt system so that cyanuric acid residues do not impair the formation of free chlorine.

3. Biguanides are a chlorine alternative

The biguanides (also called PHMB) are highly effective for disinfecting the pool and gentle on swimmers – it is also often used in the medical field.

The agent can be used against most algae, germs, and fungi in your pool.

Unfortunately, it is not effective on its own against organic contaminants such as sweat and urine and therefore has to be treated with an additional hydrogen peroxide combination.

You can also buy the biguanide as a ready-made combination with hydrogen peroxide as a liquid agent.

For the application, 1 liter of biguanide is used for every 10 m³ of pool water. A pool with 50 m³ needs 5 liters, added every two weeks.

Warning: Before using the biguanide, the pool must be completely drained, and the chlorine must be removed entirely from the pool floor and walls. Bromine and other products based on silver and copper must not be left over either.

Therefore, the use of biguanide is particularly recommended in spring when cleaning the pool after winter.

4. Ozone-Bromine combination as a chlorine alternative

Bromine is often mentioned in forums and other advice books as an alternative to chlorine.

But due to the significantly weaker oxidizing power and the poor solubility, bromine is not a real alternative to chlorine – In addition, bromine is significantly more expensive than chlorine.

A combination between ozone and bromine appears to be much more practical.

Due to the nature of the ozone (decomposes quickly), the ozone cannot simply be ordered online and must be produced directly at your pool in a special ozone generator.

It is worth mentioning that the ozone is highly toxic and should not get into your pool water. Therefore, an activated carbon filter closes the system to filter out the ozone.

Since the actual disinfection of the pool water using ozone takes place in a closed system and only works as long as the pool pump is running, an additional disinfectant such as bromine must be used in addition to the correct use of the ozone generator.

The pool pump does not run for 24 hours, and therefore it is essential to use additional pool chemicals in your pool added to the ozone.

Is the ozone-bromine combination in the private sector better than the process with salt electrolysis?

Probably not.

5. UV light and active oxygen

Ultraviolet light (UV light) is used in many areas of application to kill germs. Suitable systems (UVC clarifiers) are also available from pool shops.

In principle, the UVC clarifier works like the ozone generator: The water that has already been filtered in the sand filter system flows through the UVC clarifier, and the UV rays kill microbes and other germs.

The disinfection of the pool water also takes place here in a closed system. But that only happens when your pool pump is running.

For this reason, in addition to disinfecting the pool with UV rays, another disinfectant such as active oxygen (or bromine) must be used.

This is important because otherwise, your pool water will be cloudy if the pool pump is inactive.

Conclusion: UVC clarifiers are a real alternative to chlorine combined with active oxygen. The prices are comparatively fair, and installing the existing filter system is done quickly.

The problem, however, is that you still have to control the water levels ​​for the oxygen or bromine. At the same time, with the salt electrolysis system, the dosage takes place automatically, and controls are less necessary.

6. Pool ionization of the water

The last method to maintain your pool without chlorine is pool ionization.

With the help of electrolysis, copper, zinc, and silver ions are released that disinfect your pool water.

But again, there is the problem that no disinfection takes place when the system is inactive.

As already mentioned with the ozone generator and the UVC clarifier, an additional disinfectant such as hydrogen peroxide must be used in addition to the system.

In addition, there are the relatively high costs of purchasing a suitable system.

How to clean a chlorine-free swimming pool?

The first step towards a chlorine-free swimming pool has been taken by not using chlorine in your pool and choosing a suitable system for disinfecting the water.

However, the water in your pool must be treated with additional systems and resources to maintain the water balance. 

The crystal clear pool can quickly tip over and turn into a green pool if that doesn’t happen.

In the following text, you will find out what else you should look out for in a chlorine-free pool.

Pool cleaning with the sand filter system

The pool has to be clear, and there is hardly anything more important than using a pool pump in combination with the sand filter system – Of course, other filters, such as the cartridge filter, are also suitable.

However, the pump and the filter alone are not sufficient. Above all, the filter run times are decisive.

Especially on hot summer days, long filter run times are important for the water balance.

The pump must run for at least 6 to 8 hours a day to keep your pool water clean. Otherwise, your pool can tip over quickly and lead to green pool water.

If the pool has become cloudy, a pool shock with chemicals must often take place so that the water becomes clear again.

These are, in turn, extra costs that arise from water maintenance.

A high-performance system technology combined with sufficiently long filter runtimes can save pool maintenance costs in the long term.

In my blog, under the category pool pumps, you can find more information about the filter runtimes. Simply use the search function.

Remember: No pool chemistry can replace a good filter system in your pool.

It is important that you – as the pool owner – maintain your filters and backwash the sand filter at regular intervals.

Tip: Be sure to use a flocculant in your pool to increase the filter performance.

Pool maintenance with a pool vacuum

No matter how powerful a pool pump is, coarse dirt (leaves, sand, insects, colloidal substances, etc.) that has settled on the bottom can only be removed from the pool with difficulty with the filter system or the floor drain.

If the dirt is not removed early on, bacteria and algae will develop in the pool, which will cloud the water.

This is where the pool vacuum comes in. The dirt in your pool can easily be vacuumed off with a pool vacuum.

The advantage of a pool vacuum is that it works without direct electricity and is connected to the existing filter system in your pool – the dirt that is sucked in remains in the filter until the next backwash.

An alternative to manual pool vacuums is the automatic pool vacuums or the electric pool robots. You can find more information about vacuum robots in my blog.

Conclusion: Chlorine-free pool maintenance since the 80s

In the past few years, pool maintenance without chlorine has increased significantly.

Shops lure with multi tablets for water treatment and promise that the pool will stay clean even without chlorine, but it’s not that easy.

On average, the chlorine-free agents are sold 50% more expensive than conventional di-chlorine or tri-chlorine. With a bathing season of 5 months, these costs should not be underestimated.

In addition, switching to a water treatment system that works without chlorine is quite expensive.

But it is astonishing that pool maintenance without chlorine has been possible since the 80s.

However, these agents were not in as much demand as regular chlorine.

This was certainly due to the high costs and because many people were unaware of the consequences of using excessive chlorine in the swimming pool.

With the increasing awareness of the use of chlorine and the further development of technology for water treatment in private pools, the alternatives to chlorine mentioned above have emerged.

Some agents and systems represent a true alternative to chlorine in your pool, and others have slight weaknesses in their functionality.

In terms of efficiency and environmental compatibility, water treatment with the help of salt electrolysis seems to be a way of disinfecting the swimming pool without chlorine in the long term.

I explained how to run a pool without chlorine, and now all you have to do is choose a suitable system that fits best to your preferences.

Do you have any further questions on how to keep a pool clean without chlorine?

Contact me at @contactswimfool on Facebook, Twitter, Pinterest, and all other popular social media – I’ll be happy to help.

Happy swimming!

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Hi. I'm Max Berg. I've been in the pool industry since 2015 and have always felt drawn to water. I'm the author behind swimfool.com, where I share my years of experience in pool maintenance and give helpful tips on keeping a swimming pool or hot tub clean. My tips reduce the costs of water treatment and protect the environment.

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