Bromine Vs. Chlorine?

[simonc]

It’s time to change the water in my hot tub.

Currently, I’m using Chlorine (diclor-then-bleach method) and I’m considering the possibility of switching to a bromine based system. It’s not that I’m unhappy with using bleach, I’m just not familiar with the proper use of bromine and I’m wondering if there might some advantages.

Here are my questions:

1. What are the pros/cons of chlorine vs. bromine systems?

2. Is using a floater with bromine tablets an effective way to keep sanitation levels at the proper level? (I like the idea of a floater because I don’t have to add bleach every time I use the tub. Also, when I’m away on vacation, a floater makes sense.)

3. Is developing high levels of CYA a problem with continuous use of bromine tablets?

4. Are there any special problems with bromine hot tub water balancing or tub maintenance? pH,etc?

I know bromine is more expensive than chlorine, but the convenience might be worth it.

Thanks,

- Simon

[chem geek]

The main advantage with bromine is that you can use a floating feeder to provide bromine even when not using the tub, thus being less maintenance. If you don't use the tub regularly or don't want to check it more than once a week, then bromine in a floating feeder is the way to go. The setting on the feeder would be such that it would maintain a bromine level when the spa is not in use. You would still add some sort of oxidizer (chlorine or non-chlorine shock, MPS) to activate more bromine after you used the spa. All of this presumes you start out with an initial bromide bank started by adding sodium bromide initially.

There isn't an issue with CYA when using bromine unless you were to use Dichlor as your oxidizer. Usually you would use MPS or possibly bleach. If the pH tends to rise in the tub, then using MPS, especially an unbuffered MPS, can double as an acid to lower the pH. Though there won't be a buildup of CYA, the use of tablets will build up 5,5-dimethylhydantoin (DMH), but the amount of buildup should be low if you only use tablets for a background level of sanitation and use MPS or bleach as your primary oxidizer after each soak. DMH may have some effect on bromine similar to CYA, but it may take a lot more DMH to get to the point of being a problem -- it doesn't reduce bromine effectiveness to the same degree that CYA does with chlorine.

The only other main difference with bromine it smells different and some people don't like it; but others don't like chlorine so you'll just have to see. With bromine in the floater, however, you'll always be having some bromine in the tub. Bromine is a weaker oxidizer than chlorine so it's a little trickier to keep the water clear longer though with judicious use of sufficient oxidizer, it can be done (though maybe not for 6 months as with Dichlor-then-bleach) -- at least from what I've seen on this and other forums in terms of user reports.

Note that Hillbilly Hot Tub has found that DBDMH tablets work better with less issues than BCDMH, the latter being both bromine and chlorine.

[simonc]

Chem Geek -

Thank you for your detailed answer.

In searching previous threads in this forum, I haven't found any comprehensive writeups on using Bromine in a hot tub. I'm looking for something similar to what Nitro has done for Chlorine based systems, like this one. Does a good "primer" on bromine exist?

I like to understand (to the best of my abilities/time) things that I use. After reading a lot about Chlorine sysems on this forum, I have a much better understanding of what I'm doing with Chlorine (and other related factors, e.g. CYA). I would like to better understand how bromine systems work before I decide to make a switch.

- Simon

[The Pup]

Bromine is a weaker oxidizer than chlorine so it's a little trickier to keep the water clear longer though with judicious use of sufficient oxidizer, it can be done (though maybe not for 6 months as with Dichlor-then-bleach) -- at least from what I've seen on this and other forums in terms of user reports.

The easiest long-lasting clear water I have ever know in nearly 40 years of continuous spa ownership is my means of Bromine and MPS...I have not incurred the issues stated above.

We do not have any smell concerns...perhaps because we are able to maintain proper sanitation levels with quite low levels (1.0ppm +/-0.5ppm) using a floater (with mineral cartridge) and the spa's ozone generator.

However, if I had to buy my spa chemicals from the local spa shop (vs. online in-bulk), I would be back pouring Clorox in a heartbeat.

[chem geek]

Having an ozonator would mostly alleviate the oxidation issues I mentioned.

As for a writeup on bromine, there is this one written by waterbear.

[kbaumann]

Could someone give me a example of DBDMH tablets from either Leslies Pools or Thespadepot.com???

[quantumchromodynamics]

Brilliance MSDS

The principal chemical in the Brilliance for spas product line, Brilliance Sanitizer is a concentrated source of active bromine. This 100% chlorine-free product dissolves slowly and evenly in spa floaters to provide continuous sanitization of your spa.

http://www.nationaldiscountpoolsupplies.co...bsofbrsafo.html

http://www.archchemicals.com/Fed/BRL/Products/care.htm

http://www.valleyaquatic.com/msds-sheets/d...onder-brom.html

DBDMH = 1,3-Dibromo-5,5-dimethylhydantoin