Is Bromine Acidic or Basic

After being around water treatment and pools so long I’ve often seen alternative sanitizers but what makes chlorine so popular is its abundance and the fact that most pool owners are unaware of other trustworthy viable alternatives like Bromine which works mainly the same as Chlorine. Is Bromine Acidic or Basic?

Bromine is acidic with a pH of 4 & will reduce the pH level of your swimming pool, the effect is only a small difference from that when using chlorine, still, it’s easier to make adjustments. As a result, you can achieve the ideal pH balance of your pool water’s chemistry more easily.

People can use Bromine as an oxidizer that will remove electrons from another compound, algicide a compound that kills algae, or a sanitizer or disinfectant, basically just like chlorine doing the same job in your swimming pool.


Is Bromine Acidic or Basic


Bromine has a low acidic pH of around 4, and using bromine tablets will slowly lower pH and alkalinity over time, requiring additions of a base chemical to raise pH and alkalinity. The same can be said for chlorine tablets, which have a pH even lower, around. Bromine is far less affected by pool or spa water’s basic pH than chlorine and is able to be an active sanitizer at high pH levels of 7.8 – 8.2.


Bromine Element: Chemistry Acid Substances


Bromine is a chemical element with the symbol Br and atomic number 35. It is a member of the halogen group in the periodic table, along with fluorine, chlorine, iodine, and astatine. Bromine is a highly reactive element and exists as a diatomic molecule (Br2) under standard conditions, appearing as a dense, reddish-brown liquid at room temperature. It is the only nonmetallic element that is liquid at room temperature.

In terms of its chemical properties, bromine is a strong oxidizing agent and can react vigorously with various substances, including acids. When bromine reacts with acids, it typically forms bromide ions (Br^-) and other products depending on the specific acid involved. The reaction between bromine and acids often involves the displacement of hydrogen ions (H^+) from the acid molecule by bromine atoms or ions.

For example, when bromine reacts with hydrochloric acid (HCl), the following reaction occurs:

Br2 + HCl -> HBr + Cl2

In this reaction, bromine displaces hydrogen from hydrochloric acid, forming hydrogen bromide (HBr) and chlorine gas (Cl2).

Similarly, bromine can react with other acids such as sulfuric acid (H2SO4) or nitric acid (HNO3) to form bromide salts and other products.

It’s worth noting that bromine is a versatile element used in various industrial processes, including the production of flame retardants, dyes, pharmaceuticals, and agricultural chemicals. However, due to its toxicity and environmental concerns, its usage is regulated in many applications.

Testing for bromine chemistry is accomplished with the use of a chlorine test kit, or a DPD chemistry test kit. There are Bromine test kits labeled as “Bromine Test Kit”, but they are simply chlorine test kits, slightly modified for use with Bromine elements. If you are using a chlorine color comparison chart with test strips, or matching colors with a test kit comparator for chlorine, multiply the result by 2.25 to convert a chlorine test to a bromine test.

Aqueous hydrogen bromide is known as hydrobromic acid, which is a strong acid (pKa = −9) because the hydrogen bonds to bromine are too weak to inhibit dissociation. When added to water, bromine forms hypobromous acid. Hyprobromous acid is a weak acid.


  • Where is Bromine Found 

  • Bromine is primarily found in nature as part of various compounds rather than in its elemental form. It is relatively rare in the Earth’s crust, with an average abundance of about 2.5 parts per million (ppm). The most common source of bromine is in the form of soluble bromide salts, such as sodium bromide (NaBr) and potassium bromide (KBr), which are often found dissolved in seawater and certain salt lakes.Seawater is the largest reservoir of bromine, containing an estimated 65 parts per billion (ppb) on average. Bromine is extracted commercially from seawater through a process called electrolysis, where an electric current is passed through the water to separate the bromine ions from other dissolved ions.

    Additionally, bromine can be found in some minerals and brine deposits, where it occurs as bromide salts or in combination with other elements. Bromine-containing minerals include bromargyrite (silver bromide) and bromellite (beryllium bromide). Certain salt lakes and inland seas, such as the Dead Sea and the Great Salt Lake, also contain significant amounts of bromide salts.

    Bromine is also released into the atmosphere through volcanic activity and other natural processes, where it can react with other compounds and cycle between various forms before eventually being deposited back into the Earth’s surface.

    In terms of human activities, bromine compounds are widely used in industry, particularly in the production of flame retardants, pesticides, pharmaceuticals, and dyes. However, the release of bromine-containing compounds into the environment can have environmental consequences, including ozone depletion and potential health risks. As a result, the usage and disposal of bromine-based chemicals are regulated in many countries to minimize their impact on the environment and human health.

What are the differences between Chlorine vs Bromide in a pool

  • Chlorine(Cl) works faster to kill contaminants but for a shorter period, as it dissipates faster.
  • Bromine(Br) a more stable chemical kills contaminants more slowly but for a longer period & can help keep H2O chemistry .………………………….. Read more



How do you Switch From Chlorine to Bromine Sanitizer?

To switch from chlorine to bromine:

  • Stop using chlorine
  • Empty pool to ¾ min. level
  • Clean filtration system by backwashing
  • Make sure there is no more Chlorine stabilizer (CYA) in H2O
  • Begin using bromine tablets
  • Replace floater/chlorinator to prevent chlorine residue…………………………………………….. Read more

What are the Advantages and Disadvantages of Bromine Use

The use of bromine and bromine-based compounds offers several advantages and disadvantages across various applications. Here’s an overview:

Advantages of Bromine Use:

  1. Flame Retardancy: Bromine compounds are highly effective flame retardants and are commonly used in materials such as plastics, textiles, and electronics to reduce the risk of fire.
  2. Water Purification: Bromine is utilized as a disinfectant in water treatment processes, particularly in swimming pools and spas, where it helps to kill bacteria, algae, and other microorganisms.
  3. Pharmaceuticals: Bromine compounds are used in the synthesis of pharmaceuticals and can have therapeutic properties in certain medications.
  4. Agriculture: Bromine-based pesticides are used to control pests and diseases in crops, contributing to higher yields and improved crop quality.
  5. Industrial Processes: Bromine is utilized in various industrial processes, including the production of dyes, pharmaceuticals, and organic chemicals.

Disadvantages of Bromine Use:

  1. Environmental Impact: Bromine and bromine-containing compounds can have adverse effects on the environment, including ozone depletion and the formation of persistent organic pollutants (POPs). Brominated flame retardants, in particular, have been associated with environmental persistence and bioaccumulation in ecosystems.
  2. Health Concerns: Some bromine compounds are toxic to humans and animals, and prolonged exposure can lead to health issues such as respiratory problems, skin irritation, and neurological disorders. Additionally, certain bromine-based pesticides have been linked to potential health risks.
  3. Regulation and Restrictions: Due to environmental and health concerns, the usage of certain bromine-based compounds is regulated or restricted in many countries. This can impact industries that rely heavily on bromine for manufacturing processes.
  4. Ozone Depletion: Bromine compounds, particularly brominated flame retardants and halons, can contribute to ozone depletion when released into the atmosphere. Ozone depletion can lead to increased ultraviolet (UV) radiation reaching the Earth’s surface, which poses risks to human health and ecosystems.
  5. Persistence in the Environment: Some bromine compounds are highly persistent in the environment, meaning they can remain in soil, water, and air for extended periods, leading to potential long-term impacts on ecosystems and human health.

Overall, while bromine offers various benefits in terms of flame retardancy, water purification, and industrial applications, its use must be carefully managed to minimize environmental and health risks. Efforts to develop alternative, less harmful substances and improve waste management practices are important for mitigating the negative impacts associated with bromine use.

What Alkalinity Should Bromine Pool Water Have


Taylor Service Complete Pool Water Test Kit K-2006C

Bromine tablets generally have a pH of around 4, therefore, pH adjustment to the water will be necessary to maintain proper water balance. Even though bromine is effective over a wide pH range, it is important that the ANSI/APSP/ICC-11 recommended pH range of 7.2 to 7.8 and alkalinity range of 60 to 180 ppm be maintained.

According to ANSI/APSP/ICC-11 -Standard for Water Quality in Public Pools, the ideal range for bromine is 3 to 4 ppm for pools and 4 to 6 for spas. Test kits designed for measuring bromine are widely available.

Note that when testing for bromine with a chlorine test kit, the reading should be multiplied by 2.25 to obtain the bromine concentration. Additionally, Oxidation-Reduction Potential (ORP) may be used to test bromine-treated water; however, the reading will be lower than that obtained for chlorine.

Current test kits and test strips will not distinguish between free and combined bromine. Both will test as free. Take a look at a great test kit made by Taylor sold on Amazon and recommended by us here at MyWaterEarth&Sky Taylor Service Complete Pool Water Test Kit K-2006C


Testing for Bromine in Pools


Even in tablets where chlorine is a component, or in systems that employ sodium bromide and chlorine together, HOBr is still the primary sanitizer present in the water. This occurs since hypochlorous acid (HOCl) readily reacts with bromide ions in solution to make a new molecule of HOBr and a chloride ion (Cl- ).

Bromine has a low odor and is effective over a wide pH range. In the recommended pH range for swimming pools of 7.2 to 7.8, HOBr formation remains over 90 percent. At a pH of 8.0, HOBr formation is still 83 percent compared to HOCl formation from chlorine at 23 percent.

For this reason, in systems where pH may drift upward for short periods (i.e., hot tubs and spas) bromine is a popular choice

Bromine tablets are typically fed into the water via either a floater or a bromine feeder. Care should be taken when selecting the appropriate delivery system since the two predominant types of bromine tablets dissolve at different rates.

Once bromine is used in a pool, it will remain a bromine pool, even if bromine is discontinued and chlorine is used. A popular misconception is that the pool must be drained to switch to chlorine.

While that is the quickest method of converting a pool to chlorine, a pool with bromine or bromide ions can switch back to a chlorine pool over time. The greater the amount of oxidation and the greater the amount of sunlight present, the shorter the conversion time. Keep in mind that during the conversion process, chlorine demand will remain high.

As with chlorine sanitizers, it is recommended to periodically shock oxidize the water when using bromine tablets. Product label directions should be consulted to identify the type and frequency of supplemental oxidation treatments.

Bromine is an effective algaecide, particularly against difficult-to-control mustard and black algae, and its algaecidal properties are well known. Sodium bromide, as a source of bromine, has been EPA-registered as an algaecide.

However, sodium bromide alone will not kill algae. To be effective, it must be used in conjunction with an oxidizer, typically chlorine. If using sodium bromide as an algaecide, ensure that the product is EPA registered for that purpose and follow all label directions.

Bromine tablets, granular bromine, and bromine systems are oxidizers and must be handled properly. Avoid contact between bromine tablets or bromine compounds and easily oxidizable materials such as ammonia, urea, nitrogen-containing compounds, strong reducing agents, and other oxidizers regardless of their structure.

*Never place bromine tablets or compounds in any chemical feeder or floater with any other chemical, including chlorine.



 How to Raise Bromine Level in Pool?

  • Shock the pool if the bromine level falls below 2.0 ppm
  • Increase the dial setting on Brominators
  • Add pucks to floaters
  • Open bleeders on pool floaters
  • Increase the number of pucks in skimmers
  • Lengthen the pool’s pump run time .……………………………………………… Read more


JimGalloway Author/Editor



American National Standard for Water Quality in Public Pools and Spas



  1. What are the main uses of bromine? Bromine is used as a flame retardant in materials, a disinfectant in water treatment, a precursor in pharmaceutical synthesis, and a component in pesticides, among other industrial applications.
  2. Is bromine harmful to human health?  Bromine and some bromine compounds can be toxic to humans if ingested, inhaled, or absorbed through the skin in large amounts. Prolonged exposure to high levels of bromine may cause respiratory issues, skin irritation, and neurological disorders.
  3. How is bromine extracted commercially?  Bromine is often extracted from seawater through a process called electrolysis, where an electric current is passed through the water to separate bromine ions from other dissolved ions. It can also be obtained from certain mineral deposits and brine wells.
  4. What are the environmental concerns associated with bromine use? Bromine compounds can contribute to ozone depletion and the formation of persistent organic pollutants (POPs) when released into the environment. Additionally, some bromine-based chemicals can persist in ecosystems and bioaccumulate in organisms, posing risks to human health and wildlife.
  5. Are there regulations governing the use of bromine?  Yes, many countries have regulations and restrictions on the usage of certain bromine-based compounds due to their environmental and health impacts. These regulations aim to minimize exposure and mitigate potential risks associated with bromine use.
  6. Can bromine be replaced with safer alternatives?  Efforts are underway to develop alternative flame retardants and other substances that are less harmful to human health and the environment. However, finding effective replacements for bromine in certain applications remains a challenge due to its unique properties and versatility.
  7. What should I do if I encounter bromine exposure?  If you suspect exposure to bromine or bromine-containing substances, it’s essential to seek medical advice immediately. In case of skin contact, rinse the affected area with plenty of water, and in case of inhalation, move to fresh air and seek medical attention if symptoms persist.
  8. Is bromine safe for use in swimming pools and spas?  When used properly and in accordance with recommended guidelines, bromine is considered safe for disinfecting swimming pools and spas. However, improper handling or overexposure to bromine can pose risks to swimmers’ health, so it’s essential to follow dosage instructions carefully


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