Bromine VS. Chlorine

Whenever it is about pool or spa sanitization the first product that comes to our mind is chlorine. Since childhood we had been listening about chlorine and its use but bromine???? What is it?

We aren’t playing a quiz game here today, don’t worry!!

chlorine and bromine

Let me throw some light on this and elaborate further. Of course, chlorine comes to our mind immediately but let me tell you that bromine though a bit uncommon is similar to that of chlorine in many ways.

You yourself can assume that without a pool sanitizer you will be left with a tub or spa filled with just bacteria, soap residue, and skin cells.

Hence, bromine is also an alternative to sanitize pools and spas. Whether you are a newbie or a veteran pool spa owner bromine or chlorine both can be used as effective disinfectants.

If you want to keep your pool away from icky hazards then a good knowledge about both the sanitizers will add worth to your pool or spa. What are the basic differences between the two bromine/chlorine? Both of these have benefits and downsides, which have been explained nicely below.

Which is the best choice? Let us find more on this….

Basically, What Are They?

On a periodic table of elements these are situated very near to each other. They could prove to be dangerous in their elemental state and the good thing is that what we use for our spa or pools are actually chemical compounds.

As a free element in nature Bromine is far too reactive. This is more commonly found in two compounds:

  • Sodium Bromide (Na Br).

  • Potassium Bromide (KBr).

Both of these are found in seawater.

Their Physical Form

The availability of Chlorine is in various different forms.

bromine versus chlorine

  1. Tablets
  2. Sticks
  3. Dry granular state

The most common form in which they are being used is the chlorine tablets. Usually, pool owners use an automatic or floating feeder and this is probably the least-cost option for or spa or pool maintenance.

If I detail about bromine then this is also pretty similar to that of chlorine, comes in granules, and is dispersed in a similar way.

The right way to add bromine is a floating dispenser and the tablet form is best suited.

It does, however, require its own feeder that may add to the initial cost of doing business.

The Major Differences and Features- Bromine and Chlorine

If its swimming pools then chlorine is used most commonly while the use of bromine is more common to sanitize the hot tubs. Recommended read: How long after putting chlorine in the pool can you swim.

spa bromine vs chlorine

Before you take a decision, you need to educate yourself more about the benefits, features, and drawbacks of both these products.

We have listed their differences and features based on some parameters.

chlorine vs bromine

Difference 1 – First Aspect

Their Working

Both these works to kill bacteria and any other gruesome stuff but this is not the sufficient answer. We need to know and learn more.


It oxidizes the contaminants and works to destroy them inside out.

The disappearance of chlorine after its work turns into a waste product known as chloramine. These leaves are stinky, dry, and could reduce the sanitizer’s effectiveness.

Addition of chlorine should be done on a regular basis for keeping water clear and in pristine condition. For getting rid of chloramines you can shock your tub.


It ionizes contaminants forcing apart their chemical bonds. Even after they combine with contaminants a good amount of them remain working and active.

The waste product of bromine is bromamines and this is not as harmful as the chloramines. They do reduce the effectiveness in your hot tub and shocking is also a solution here.

Difference 2- Second Aspect


The reactivity rate of a sanitizer is responsible for measuring its effectiveness. By effectiveness here, we mean how rapidly the contaminants are destroyed.

Chlorine: This is a faster killer as compared to bromine.

bromine vs chlorine spa

Bromine: This is not as reactive as chlorine though considered to be a very reactive one. This kills slower than chlorine. Even its pH levels are lower as compared to chlorine and keeps water chemistry balanced overall.

You need to adjust less and intrigue less.

bromine vs chlorine hot tub

Difference 3- Third Aspect


More stability is provided by bromine than chlorine when in warm water specifically.

Chlorine: As the evaporation of chlorine is much faster than bromine, so it needs to be replaced more often.

Bromine: The effect of bromine on bacteria is for much longer periods than chlorine.

Note: Only the UV rays and sunlight tend to destroy bromine quicker than chlorine.

Outside tubs need to be kept covered to control its effect. The chloramines tend to promote the growth of algae and breeding of bacteria. Red eyes and brittle hair could also be an underlying problem.

Difference 4- Fourth Aspect

Dosage Amounts

How much water your tub holds and in correlation to it what is the tub size. For getting the maximum benefits from any sanitizer you need to work on this.

bromine or chlorine

Firstly, you need to follow the manufacturer’s instructions and later test the water to gauge the levels.

Chlorine: The perfect level that chlorine should have is 1 ppm- parts per million to 3 ppm. So, 3 ppm remains the ideal.

There may be chances that you might end up with more chlorine levels in your hot tub then some things can be tried for lowering levels. The same is when it’s bromine. You should not worry as you don’t need to start over again.

Bromine: When its bromine the ideal level is 3 ppm to 5 ppm with 5 ppm being perfect.

As compared to chlorine you need not use a larger dose of bromine. And bromine is costlier than chlorine, but it is not required to be used often so cost may turn out to be the same for you. The size of the tub and the water maintenance also dictates the usage and cost of the sanitizer.Weighing and comparing the benefits are important when it’s about spending some extra dollars.

bromine vs chlorine health

Difference 5- Fifth Aspect

Your Health

If used with the chlorine and bromine in the right amount they tend to be safe for you. though some people may react differently.

Anyone’s health is of prime concern and this difference holds great importance as you can never compromise with your health and safety.

Chlorine: If the levels are too-high this can be harsh on skin, eyes, and hair.

If there are chloramines and they loiter in humid air around then there are chances that breathing difficulty could happen to some and asthma attacks could trigger.

Expert Advice: Anyone of you with extremely sensitive skin or with some kind of upper-respiratory issues should go for bromine as this will turn out to be the ideal choice.

Bromine: As compared to chlorine its effect on skin is gentle but washing it off could be difficult after you soak for long hours.

Using Chlorine and Bromine Granules

It is simple, if you know how to use a measuring cup. The granules of both the sanitizers can be easily added to the hot tub or pool.

  • The hot tub or pool volume needs to be determined/water capacity.

  • The instructions should be read carefully on the container.

  • The amount of chlorine or bromine should be measured accordingly.

  • The granules should be poured slowly and directly in water.

  • The water should be allowed to circulate for 20 minutes as the sanitizer disperses.

  • The sanitizer levels should be checked properly and adjustments should be done if needed.

Using Chlorine and Bromine Tablets

You won’t be adding them as granules all the time, and would be using them as tablets also. Though making use of tablets is also not a complete set-it-and-forget-it method.

bromine instead of chlorine

  • The manufacturer instructions should be read on the container and followed carefully.

  • The recommended number of tablets should be placed inside the floater or a feeder. Usually, 1-inch tablets to be placed in whatever dispenser you use for your pool, spa, or hot tub.

  • The feeder should be adjusted according to the directions for controlling the sanitizer release.

  • The feeder/floater/dispenser/ should be placed underwater for a few seconds in the pool/hot tub for ensuring stability while it floats as the air pushes out.

  • For a couple of days, the water should be examined for appropriate sanitizer levels. Make any adjustments if needed.

Few Safety Tips Which Are Essential

Whatever you choose out of the two, PAY ATTENTION!!

  • Don’t mix them in the water together. The reason is this could cause an extremely harmful chemical reaction. For switching from bromine to chlorine or vice-versa you need to drain the previous filled water or go for a line flush.

  • They should not be mixed in their dry form and if granules then a big no. Any chemical reaction can occur.

  • Let me tell you if they are placed in the separate containers, they may emit fumes, may combine, and could become explosive.

  • The same feeder should never be used for bromine or chlorine both, be it for tablets or granules. Even if you feel they are cleaned well then also there are chances of any chemical reaction to happen with the remnants.

bromine or chlorine for hot tub

Which One Should Be Preferred?

After considering all the above things it will be your personal preference and choice what you select for your pool or spa.

We have few tips for you:

  • If you are on a budget go with chlorine.

  • Having sensitive skin or asthma? Try bromine.

  • Residing in a warm climate? Bromine is a great option.

  • If your backyard lacks shade. Pick chlorine.

Wrapping Things

Keeping your pool or hot tub maintained is extremely important. For selecting pool and spa sanitizers the level of the sanitizers should be proper and water should be kept balanced.

The following factors rule your choice of chemicals:

  • Environment

  • Budget

  • Temperature

  • Volume of water

Since, your aim is to have a pool, spa, or hot tub to have healthy soakers and swimmers. Hence, keep your pool/spa/hot tub water healthy and the users happy.

Whichever method you go for, just ensure to remember the foundations of pool, spa, or hot tub care. Be it the granules or tablets, use the right dose (measurements) by following the manufacturer instructions.