Why can't bromine be used with nature2 silver based mineral cartridges?

[bowdrie750]

I have a huge supply of bromine and just bought a case of nature2 cartridges not realizing that the instructions said not to use them with bromine?  Does anyone know why nature2 cartridges (silver based) can't be used with bromine?  Will a toxic chemical reaction occur or will they just work better with chlorine?  Bromine is actually recommended for the spa frog and leisure time mineral cartridges which are all silver based minerals but I can't find information about why bromine can't be used with nature 2? 

[clover]

I have a huge supply of bromine and just bought a case of nature2 cartridges

Natures II and other similar "silver ion" sanitizers are usually used in conjunction with Ozone and replaced every 6 months, so you have a long time supply. 

Do you have an ozonator on your spa?

Bromine is a slowly dissolving tablet that emits di-chlor.  Its primary function is to dissolve slowly releasing chlorine over time as the sanitizing agent.  Its advantage is to "slowly dissolve", whereas chlorine must be administered almost daily, while ozone is supplied continuously while the ozonator is energized and producing a sanitizer / oxidizer.  Silver Ions will support ozonators, but as you see, not bromine.

IMO ozone is the most beneficial sanitizer for a number of reasons, chlorine second, and then there is bromine that doesn’t require your daily attention.

[Dr. Spa™ Ret.]

Trying SO had not to be derogatory........

[chem geek]

I don't know this for a fact, but I'm guessing that the silver cartridges in Nature² dissolve to release silver ions at a specific rate when using chlorine, but when using bromine they don't dissolve at the proper rate.  SpaFrog may use a different compounded material to work better with bromine.  But that's just a guess on my part.  At any rate, the silver ions in Nature² are most useful when using the low-chlorine recipe that uses mostly MPS since that is EPA-approved and a way of getting disinfection without halogens (chlorine, bromine).  If you are using bromine, especially a 3-step system including bromine tabs in a floater or if you have an ozonator, then the silver ions are superfluous.

[Dr. Spa™ Ret.]

According to Nature2, bromine causes a coating to form around the nature2 pellets sealing them from being effective.

Bromine does NOT "emit di-chlor". Bromine tablets are made up of a combination of sodium bromide and chlorine. The chlorine is used as the oxidizer necessary to convert the sodium bromide into bromine.

Ozone in my opinion, is effectively a joke, as used in spas. Yes, ozone is scientifically a more powerful oxidizer than chlorine.. but as an analogy, a bullet from a 45 is more likely to kill you than one from a 38. True? What if the 45 is pointed skyward and the 38 directly at you?

With chlorine, a known measurable amount, dissolved in water for a specific amount of time, will sanitize the water. With ozone, how much do you need? How do you control or measure this amount? Heck, it's not being absorbed into the water in any measurable amount...it's about as "deadly" as a 45 pointed skyward.

Show me ANY scientific study showing the EFFECTIVENESS of ozone used in SPAS....been asking to see this for years

[chem geek]

Thanks for the info on Nature² and its problems with bromine.  I'll now be able to answer that question more intelligently if it comes up again.

One point for correction.  Bromine tabs are not sodium bromide and chlorine.  There are two types of bromine tabs and both of them have a 5,5-dimethylhydantoin core.  The most common bromine tabs are 1-bromo-3-chloro-5,5-dimethylhydantoin aka bromochlorodimethylhydantoin or BCDMH.  The tablet releases both bromine (hypobromous acid) and chlorine (hypochlorous acid) with the DMH remaining (building up, similar to what happens with CYA when using stabilized chlorine).  The chlorine activates any bromide ion in the water which is why one normally initially establishes a bromide bank.  Another type of bromine tablet is 1,3-dibromo-5,5-dimethylhydantoin aka dibromodimethylhydantoin or DBDMH.  This tablet releases only bromine and has no chlorine.

As for ozone, I agree with you that it is not very useful in spas that do not get a lot of use since ozone reacts with chlorine so actually increases chlorine demand when there is no bather load.  However, I disagree with you in terms of it not being useful when the spa is used frequently, say every day or two.  When there is such high bather load (since the spa volume is so small), the ozone oxidizes some of the bather waste before chlorine gets a chance to react with it thereby reducing chlorine demand and also reducing the amount of formed chlorinated disinfection by-products.  We've seen this chlorine demand effect on numerous spas (mostly at PoolSpaForum) and even had people disconnect and then reconnect their ozonators to see that in fact the difference in chlorine demand was due to the ozone.  Now your points about not being able to control the ozone are quite valid and it would be better if one could control the on-time of the ozonator to better match when the ozone is actually needed.