If ozone won't create bromine from boric acid but will create it from sodium bromide, what if I was to add sodium bromide to the pool and let the ozonator make bromine from bromide? From what I've learned about bromine, it's more stable in hotter water (a south Florida problem) and over a wide pH range. And combined bromine is still a pretty good sanitizer while combined chlorine is not.
Ok, a couple of problems here. First, let's be absolutely clear about something - boric acid contains the chemical element
boron (chemical symbol
B) and contains absolutely no
bromine (chemical symbol
Br) whatsoever. Aside from starting with the letter "B", that's about all they have in common.
Yes, if you add sodium bromide to your pool, the ozonator can make some bromine out of it.
The temperature stability of active bromine compounds and active chlorine compounds is wildly overstated in most websites and is really not the driving factor in determining which sanitizer to use. Bromine, which can not be stabilized in water at any temperature, will dissipate faster due to UV loss than stabilized chlorine. So, in that sense, it's stability (rate of disproportionation and auto-oxidation) with respect to temperature is meaningless.
As for pH stability, that is fairly meaningless as well. Pool pH rise is driven primarily by the rate of CO2 outgassing in water. Liquid chlorine sources (bleach) are basically pH neutral on net balance and SWG's are pH neutral as well. Cyanurate forms of stabilized chlorine (dichlor and trichlor) are net acidic and calcium hypochlorite is net alkaline. It is these factors that determine the pH stability of pool water, not which halogen sanitizer is used.
As a matter of bather comfort, you want neither combined chlorine compounds nor combined bromine compounds in water as both are fairly strong irritants. Sodium bromide is often found in some forms of algae treatment because it will form bromine and bromamine in chlorine pools and that is a more effective algaestat, especially against black and mustard algae. But, the fact that those are "sanitizers" is irrelevant; you simply do not want them in the water in the first place.
Not being able to stabilize bromine with CYA would be a problem but I could just filter during daylight hours and run the ozonator which would continuously make bromine during sunlight. Electricity is pretty cheap in Florida and this seems like a cheap way to add bromine to the pool rather than buy it as a powder or a tablet.
You can use an ozonator [EDIT]
SWG [END-EDIT] to generate bromine from bromide. BUT, you would not want to do as you laid out; in fact, you would need to run your ozonator [EDIT]
SWG [END-EDIT] and your pool pump 24/7. Bromine can not be stabilized with respect to UV photolysis and so, after about an hour or so, most of the bromine you generated overnight will be gone. You will then have a pool completely exposed with not enough residual sanitizer to do anything useful. Bacteria can double their colony sizes in 45mins; algae doubling times are roughly 4-6 hours. Your pool would be overrun with algae and bacteria within a few days.
And I'm confused when you say that ozone is slower than chlorine or bromine as an oxidizer. Everything I've been able to read is unanimous that ozone is almost instantaneous as an oxidizer and much faster than chlorine of bromine. It's the short half life of ozone (15 seconds in 85 degree water) that is the issue rather than oxidizing ability.
Anyway I'm really grateful for your experience and willingness to discuss these wild ideas I have.
Chlorine and ozone will oxidize different chemical compounds at different rates. Because ozone has little solubility in pool water, there is no way to maintain any kind of residual. As soon as the ozonated water leaves the return fitting, the ozone will bubble out of the water. Chlorine, especially when it's stabilized with CYA, can maintain a very large residual in water. Therefore, chlorine will be vastly more effective at eliminating organic waste irrespective of individual reaction rates.
Finally, what you will find in pool grade ozone equipment is a fairly inefficient and low quality design. Ozone generators for pools are typically very weak (produce minimal amount of ozone) because they use atmospheric air as the oxygen source. The oxygen levels are sufficiently low enough in air and the relative humidity of the air is high enough to make the ozone generation process very inefficient. This is improved somewhat if the manufacturers add a dehydration filter to the intake (using a hygroscopic agent like calcium chloride) but the low concentration of oxygen gas is then the limiting step. Only in commercial grade ozone systems that employ both dehumidification and oxygen concentrators would you get substantial quantities of ozone but those systems are expensive and then you would have to be concerned with the health effects of breathing in higher levels of ozone in and around the pool area. In hot tubs with ozonators (well, ones that actually work), the ozonators are typically only run when in stand-by mode and the jets are not active.
While I'm happy to entertain the chemistry questions, your plan will likely fail. Bromine is a terrible sanitizer for pools as it is very difficult to maintain the appropriate residual levels and requires lots of extra work to even come close to getting it to work. The idea of bromine in pools violates the core principle of what is taught here -
Trouble-Free Pool.
