Dichlor vs. Bromine. What's the difference?

[bareyb]

1. I've noticed some folks use Dichlor and some Bromine. What's the difference and why do you prefer one over the other?

2. How about "Shock Treatments" such as "Renew"? How does this differ from the above and how often do you need to use those? Is this done at the same time as the Bromine or on a separate day?

[MarKee]

Dichlor is your traditional chlorine.  It does work.  Usually dichlor comes in a granular form that you pour into the spa after each use.  Bromine is a chemical that is similar to chlorine but has many differences.  Most bromine concentrations usually contains approx. 40% chlorine.  Bromine lets off less gas than chlorine does, therefore has less odor.  Some people claim that their skin is less irritated with bromine.  A lot of people will switch from chlorine to bromine  if their skin is being irritated.  I have heard of some instances where bromine has irritated skin.  Bromine is usually distributed through a floater that contains tablets.  It is also available in a granular form.  Some companies have even implemented bromine cartridge systems into their spas.  One thing that makes bromine more versatile that chlorine is that it is effective in all pH ranges, where chlorine is not very effective if the pH is not within range.  I prefer bromine, but both systems work, and we sell both at our store.

[NE-Phil]

Doc at RHTubs.com has a nice comparison of different sanitizers for hot tubs here.

Phil

[Brewman]

I've used both and find dichlor simpler and cheper.  I have to add less water adjusters with dichlor than I did with bromine.

With bromine, you use a floater or a dispenser built into some spas, to maintain a target level of the chemical.  So you're always soaking in bromine water.

With a chlorine system, you need to add small amount of the chemical periodically, since dichlor dissipates from the water fairly quickly.  You can work it so that you never soak in chlorine water if you time it right.

The problems I had with bromine:  I couln't get the level to stabilize.  Some days the reading was off the chart- way too high, and other days there was no reading at all.  Plus either the Bromine or the MPS shock I was using pulled my Ph and Alk reading down all the time, so I had to constantly add Ph up or baking soda.
Plus, some of the plastic surfaces in the spa, like the jets and weir gate got this brown stain.  It was rather easy to scrub off though.

With chlorine, I just add a couple teaspoons to the water after using the spa, and run the pumps for a few minutes.  By the next evening when we wanted to use the spa, the chlorine level would be very low so we'd be soaking in water with less sanitizer in it.  
I do add a dose of dichlor every few days if for some reason we don't use the spa during that time.  
I've heard that over time chlorine can affect things like the cover and spa pillows- so far I haven't seen that happen.

Once a week or so, I add a large dose of chlorine for shock.  I also use MPS to shock but only occasionally, like if we want to use the spa that day- with MPS you can use the spa soon after shocking.  With chlorine I choose to wait till the level drops.

With a bromine tub you can shock with MPS or with dichlor- I used MPS.  

Both worked, but in my case I prefer dichlor.

[golferm]

As an FYI to those using or looking to use Bromine....

Spa Guard has a one step granular Bromine product.  You don't have to add the liquid bromide before the granular.... just one step like dichlor.

In Canada, costco.ca also sells the Omni version of that product for a little less money.  (Omni is another brand of Spa Guard)

Mark

[Bill_Stevenson]

There is a bit of misinformation creaping into this thread.  Briefly, both chlorine and bromine are halogens.  Their purpose is to sanitize and both will do the job.  In terms of their relative effectiveness, chlorine is roughly an order of magnitude more powerful than bromine.  That fact has some important implications in terms of practical use.  First, chlorine is powerful enough to knock down the bacteria in just a few hours, whereas, bromine must maintain a residual of 3 - 5 ppm at all times to make your spa water safe.  Second, adding a teaspoon or two of dichlor after each soak is easy to do, whereas the floater for bromine has to be diddled to get it right (some people don't mind this).  Third, it is easier to adjust the dosage level with dichlor to compensate for different numbers of users.  Fouth, and this is very important, dichlor breaks down after a few hours in hot water, which means that it is possible to soak in a dichlor treated tub with very little to no residual chlorine safely.  This is a boon for people with sensitive skin.  By contrast, because bromine is weaker, you always are soaking in a tub with the sanitizer.  

A few other trade-offs:  Bromine is not broken down by sunlight, whereas dichlor is.  This could be important for those soaking in direct sunlight.  Free chlorine has no odor in the recommended concentrations of 3 - 5 ppm.  The smell that most people associate with chlorine comes from combined chlorine.  This is chlorine that has reacted with the bugs and it must be burned off periodically by shocking the tub with a dose that is 5 - 7 times greater than the daily dose.  For most users shocking is a once a week ritual.

For a full and thorough explaination of this subject go the the FAQs in www.rhtubs.com and look up the Vermonter's water treatment program.

[orlandoguy]

This whole liquid bromide thing has me confused as it isn't part of my routine.  I simply shock with mps once a week, which i was under the impression that it activated the bromine that stays in my floater.

I'm sure someone knowlegeable, like 4redcheeks, will make it all a little easier to understand.

[MarKee]

The chemical bath analogy for bromine is played out and false.  Do you know that most city waters keep a residual of .5-2 PPM?  On the Marquis constant clean system that uses a bromine cartridge as well as an ozonator, you can have your bromine residual at 1-2 PPM.  At that level it is very hard to smell, and I'm sorry but 1-2 PPM is not a chemical bath.  

[Brewman]

Perhaps not a chemical bath, but I'm not sure that my city brominates it's water- chlorine yes.
I heard that bromine causes cancer.  Now if you'll excuse me, I have a cigar to go smoke.

[MarKee]

Inhalation of chlorine has been proven in some studies to cause cancer, but there is also chlorine in bromine.

[Brewman]

Brilliance brand of bromine is chlorine free.  But yeah, lots of other bromine contains chlorine.

And the cancer thing was a joke.  That's why I put the cigar comment after it.  

I'm sure that "some studies" have found that doing or ingesting just about everything causes cancer.  
You name the product, someone somewhere has linked it to cancer, or so it seems.  

[anne]

Free chlorine has no odor in the recommended concentrations of 3 - 5 ppm.  The smell that most people associate with chlorine comes from combined chlorine.  This is chlorine that has reacted with the bugs and it must be burned off periodically by shocking the tub with a dose that is 5 - 7 times greater than the daily dose.

Very thorough, well summarized post, Bill.

Here's something that has bugged me since I got my tub: I accept the above statement as true, but if so, why does the bottle of chlorine smell like chlorine, and why does it smell "chlorine-y" when I am sprinkling it in the water?

[Bill_Stevenson]

Anne,

First of all, don't sniff your dichlor bottle.  :-)

Seriously, though, chlorine (and bromine too) is a very nasty and powerful chemical.  In it's bottle and when you are adding it to the tub, you should try very hard not to inhale it as concentrations this high would cause all kinds of health problems.  Once you have added you teaspoon or two and let it dissolve and thoroughly mix with all of the water in your tub, there will be no odor.  

Regards,

Bill

[anne]

Anne,

First of all, don't sniff your dichlor bottle.  :-)

Seriously, though, chlorine (and bromine too) is a very nasty and powerful chemical.  In it's bottle and when you are adding it to the tub, you should try very hard not to inhale it as concentrations this high would cause all kinds of health problems.  Once you have added you teaspoon or two and let it dissolve and thoroughly mix with all of the water in your tub, there will be no odor.  

Regards,

Bill

LOL! Dont worry, I'm not sticking my face in it. So are you saying that it initially has odor just because it is so concentrated, and that cannot be compared to a full tub of water at only 3-5 ppm? I still smell it at 3-5 ppm, but I do have a good nose. Sucks in my profession.

[Bill_Stevenson]

Anne,

Yes I am saying that a concentration of 3-5 ppm of chlorine, thoroughly mixed in a tub, should have no or almost no discernable odor.  It you can smell chlorine it most likely means that you have a difference between free chlorine and combined chlorine on the order of 1-3 ppm.  The solution is to shock.  You can use dichlor or MPS to shock.  I generally prefer dichlor because MPS adds more total dissolved solids, but MPS can clear cloudy water in some cases where dichlor might not.  MPS is a very powerful oxidizing agent.

Bill