Is Ozone Necessary?

[passmaster16]

I know this has been a hotly debated topic but I wanted to get some more relavant insights as many of the posts appear to be old. As I mentioned in a previous thread, I'm in the market for a midgrade tub and have been looking that the Hot Spot Tempo/Caldera Palatino.  This tub does have an optional CD Ozonator.  Now I understand the theory behind ozone - with it being an oxidizer and supposedly helps with keeping water clean requiring less chemicals, but does it really work?  For me it's not really about the price as it's only a couple hundred dollars extra, but I like to keep things simple.  If it's a feature that only adds marginal benefit, it just seems like something else to pay to maintain or fix if it breaks.  Am I wrong?  In fact, to my surprise, a salesman at one of the dealers suggested it wasn't necessary and mentioned that he has a 5 year old tub and does fine without it.  I suppose I'm just trying to find the positives and negatives of it.  Any feedback you could provide would be greatly appreciated.

Thanks in advance!

[VTXMAN]

Needed? No, do they help yes. But only if the spa is properly built with ozone in mind. A spa must have a contact chamber or the ozone is wasted. The length of the contact chamber is dictated by the GPM of the pump.

Most manufactures do not add this crucial part and therefor all they are doing is selling you snake oil. 

[Spatech_tuo]

In fact, to my surprise, a salesman at one of the dealers suggested it wasn't necessary and mentioned that he has a 5 year old tub and does fine without it.  I suppose I'm just trying to find the positives and negatives of it.  Any feedback you could provide would be greatly appreciated.

It is NOT necessary but in my experience it does help and the one way I know is the times when people have water trouble with a new spa and typiaclly I've found the ozonator has an issue and not being operational  (often just a pinched hose, bad check valve... minor start up stuff). When ozone is working the early water care issues seem much less. Not exactly scienticially proven but enough for me to draw a conclusion that it is helpful. Its not some magical elixir that takes work away for you, it simply lessens the chances of having water care issues and you won't save an equivalent $ amount in chems by using it, just some peace of mind IMO. If you can afford it I'd go for it, if you're at all skeptical or its too pricey just skip it and you can add it at any time down the line since its VERY simple to install.

[passmaster16]

It is NOT necessary but in my experience it does help and the one way I know is the times when people have water trouble with a new spa and typiaclly I've found the ozonator has an issue and not being operational  (often just a pinched hose, bad check valve... minor start up stuff). When ozone is working the early water care issues seem much less. Not exactly scienticially proven but enough for me to draw a conclusion that it is helpful. Its not some magical elixir that takes work away for you, it simply lessens the chances of having water care issues and you won't save an equivalent $ amount in chems by using it, just some peace of mind IMO. If you can afford it I'd go for it, if you're at all skeptical or its too pricey just skip it and you can add it at any time down the line since its VERY simple to install.

Thanks spatech.  I posted this on PSF as well and one of the responses there was that the ozone isn't as beneficial on a tub like the Tempo that does not have a 24 hr circ pump.  Would you agree with that assessment?

[hottubdan]

Agreed.

[Spatech_tuo]

Thanks spatech.  I posted this on PSF as well and one of the responses there was that the ozone isn't as beneficial on a tub like the Tempo that does not have a 24 hr circ pump.  Would you agree with that assessment?

Ozone definitely works better in conjunction with a 24 hr circ pump.

[Dr. Spa™ Ret.]

Can anyone show a study done by an independent peer reviewed party showing that ozone has ANY effect in spas???

[chem geek]

I haven't seen that, but I can tell you from reading many posts on spa forums (like poolspaforum that you also frequent) and having reasonably accurate FC reports using FAS-DPD chlorine tests that most spa ozonators do two things:

1) they break down chlorine into chloride and chlorate ions
2) they oxidize bather waste

These two effects compete with each other with the net result that spas that are infrequently used, say once or twice a week, end up with the daily chlorine demand in between soaks getting doubled to roughly 50% of the FC level instead of the more usual 25% of the FC level.  If a spa is used frequently, every day or two, then the chlorine demand is roughly cut in half since the ozone oxidizes bather waste so that less chlorine needs to be added.

Of course, the exact amounts depend on the strength of the ozonator and actual bather load, but roughly speaking the above works as a reasonable rule for a lot of spas with ozonators.  This generally means that ozonators are helpful in spas with high bather load (i.e. used frequently) and not helpful in those with low bather load (i.e. used less frequently).  They do not prevent cloudy water problems in between soaks -- chlorine still needs to be added to prevent the water from going south and to prevent biofilm formation on surfaces.

[BNMac]

How does the ozone work with bromine?  I have a floater which maintains the bromine level.  The tub has a 24 hour recirc pump.

Our tub sees varying use - sometimes it's a week or two between uses, other times it's used daily.

[chem geek]

Mostly ozone reacts with the bromide ion bank and creates more bromine.  So with a functioning ozonator, one would normally turn down or even remove the floating feeder, so long as the background bromine level is maintained.  There might still need to be addition of an oxidizer after a soak if one uses the spa frequently (every day or two) or one might use the bromine in a floater to supplement along with the ozonator.

Ozone will also react with bromine to from some bromate so over time the bromide ion bank will slowly get depleted so you either need to create a large enough bank to start with or need to add some more sodium bromide every so often (or use bromine tabs in a floater since that will also replenish bromine/bromide).  Unfortunately, I don't have any good data to tell you typically how fast this depletion occurs.

[Steve]

Wouldn't a real study be so amazing?!?!

Here's how how I look at ozone and I'm trying to attempt to remove the Beachcomber kool-aide for all of those years...

Like anything (I'm replacing windows in my home currently...) I look at the payback. If I purchase ozone understanding there's an upfront cost and I will need to replace that chip/bulb every couple of years, I then need to consider that if my total cost to add this "feature" to my tub has cost me $300 or $400 over a 5 year term, did it actually save me anything?? 

The other issue that most saleman make up the savings amount on your monthly chemical costs. I've heard ozone can save you anywhere from 20-90% depending on who you are talking to. Again, there is no study to back up any of these numbers...

Steve

[ndabunka]

They are not NECESSARY but they are a nice convenience.  I agree that they reduce the amount of chlorine required.  I've used di-chlor ONLY since day-1.  Only the UV-based Ozonators need to be replaced every 2 to 3 years.  The CD-based ozonators tend to last 7-8 years.  The CD-based ones cost about twice as much but last 3-4 times longer.  Seems a no-brainer.