Ozone Question. (Very Technical)

[Ehizzle]

Ok so I have this strange desire to know exactly why something works the way it does, not just that it does. We all know that Ozone is not a stand alone sanitizer. Please don't crucify me, Ozone worshipers. Not one ozone manufacturer stands behind that faulty believe. What I want to know is why? I have seen sites that say it sanitizes most of the water but still needs some chlorine to finish it off. I have seen sites that say, "ozone can only oxidize after it has become a chloramine." I have even seen one site say that Ozone sanitizes but doesnt oxidize. Which is hosh posh.

So, anyone know the actual capability of Ozone and why it still needs chlorine?

[Vinny]

Ozone is a contact sanitizer/oxidizer. If a molecule of O3 comes in contact with something it destroys it (plastics too). Once O3 is used up or dissipates it no longer has any effect on anything.

In drinking water temps I believe the life span of ozone is about 20 minutes, so it's hanging around in the water possibly bumping into ((actually there is a ionic charge to O3 and it is electrically attracted to a substance) keep in mind that the distance we are talking about is very small, probably microns or smaller(nanometers)). In drinking water, the water companies add chlorine to kill any organisms that might start to grow when the ozone is depleted.

In spa water the life of O3 is 20 seconds. Everything else is the same.

I hope this explanation helps!

[Gomboman]

I'm not sure if this answers your question but I found this from:

http://www.askalanaquestion.com/ozonators_for_spas.htm



Ozone (O3) is a form of oxygen (O2) and is a powerful oxidizing agent that can help control microorganisms, destroy organic contamination, build up byproducts, dead algae and organic debris.   It is not a complete spa or hot tub sanitizer, in the truest sense, because ozone does not remain in water for long periods of time.  There must be a backup sanitizer such as:  chlorine, bromine or ionization.  An Ozone Purification System will reduce the quantity of the backup sanitizer required for proper sanitation.  The devices that generate Ozone fall into two categories:  UV or Corona discharge.  Commercial spas and other high bather usage installations should utilize a corona-discharge type of unit, as it is capable of producing the greater quantities of ozone that these situations require.  With ozonation, the water should be maintained in the typical manner.  

[Ehizzle]

Great responses. The only thing about those aspects that has had me confused is this. If you have an ozonator in a spa on 24/7 it shouldnt matter how fast it dissapates right. Or, do you think that because ozone is so strong you arent able to put enough ozone into the spa to where it would handle everything in the contact chamber before it dissapates. That I guess would makes sense. I guess its kinda a hard thing to describe or really see in your minds eye.

[tileman]

Great responses. The only thing about those aspects that has had me confused is this. If you have an ozonator in a spa on 24/7 it shouldnt matter how fast it dissapates right.

That was what I was pondering as well.

[Dr. Spa™ Ret.]

How much ozone are you putting in the spa? SERIOUSLY, how much? A lot of people say to add 1 tsp of chlorine for each person when you exit the spa. So, HOW MUCH ozone do you put in? How much ozone does your ozonator put in in a 24 hour period? How do you measure how much ozone is actually being absorbed into the water (cause if it aint absorbed, it aint doing much good)?

There's a lot of different ozonators, that produce quite varying amounts of ozone. There's many different ways ozone is introduced into the water. Some morte effective than others.

When talking about chlorine, everyone talks in specific measurements. People frequently ask or advise on how much chlorine to put in, do think there might be any importance to how much ozone is put in as well?

[Vinny]

What Doc says is true.

Other than from spa ozone maker sites, real info is based on drinking water ozonation and that technology is different than spa ozone.

First off they use 100% O2 and high power 6,000 volts, spas use 21% (air is 21% O2) and I don't believe even a CD ozonator generates high voltage. They use 40 foot contact chambers and reverse flow technology. But probably the most important is they monitor it all through the various stages and adjust output to get the needed amount of O3 to be effective.

[Ehizzle]

What I do know is that you need 250ppm of Ozone for it to be effective. The only Ozonator I know specific amounts of is the Hot Spring Freswater 3 which produces 600-900ppm, which I'm pretty sure is higher than most. Also, since you need 250ppm of Ozone, alot of the people who have UV Ozonators and haven't changed the bulb just because it still gives off light are using a useless product. I also think that putting an Ozonator on a spa that doesnt run 24/7 is worthless, since it only lasts about 20 minutes. Then those same people think they dont need to add anything else and they end up with a big unsanitized mess.

[Dr. Spa™ Ret.]

What I do know is that you need 250ppm of Ozone for it to be effective.

Most ozonators are rated in grams per hour that they produce.

parts per million of what? Are you talking of the air as it exits the ozonator?

"The air exiting the ozonator needs to be a minimum of 250ppm of ozone to be effective" (?)

Can I ask how you know this? I've never, in over 25 years, heard this before (seriously, while I'm not a proponent of ozone, I'm always looking for info and willing to learn new things.)

Is there any relevance as how much of that ozone is actually absorbed into the water??

Considering ALL the various industries that use ozone, are there different methods of achieving absorption, and are some more (much more) effective than others? Which is the most/least effective?

Vinny...... not only pure O2, but also zero moisture content and cooled.

[Vinny]

What I do know is that you need 250ppm of Ozone for it to be effective. The only Ozonator I know specific amounts of is the Hot Spring Freswater 3 which produces 600-900ppm, which I'm pretty sure is higher than most. Also, since you need 250ppm of Ozone, alot of the people who have UV Ozonators and haven't changed the bulb just because it still gives off light are using a useless product. I also think that putting an Ozonator on a spa that doesnt run 24/7 is worthless, since it only lasts about 20 minutes. Then those same people think they dont need to add anything else and they end up with a big unsanitized mess.

"What I do know is that you need 250ppm of Ozone for it to be effective" - Where did you get this info from? I've never found anything in my research (it's been a while) saying an actual amount. Most ozonator companies from what I've found give output in Grams per hour ... I don't know what's that in PPM.

There are some "facts" that are questionable.

 "Hot Spring Freswater 3 which produces 600-900ppm" - is this dissolved or produced. If whatever ozone produced doesn't gets dissolved it isn't being used. How do you know that this amount is being introduced? What is the test equipment used to find this out in a given tub?

"alot of the people who have UV Ozonators and haven't changed the bulb just because it still gives off light are using a useless product" - it may be true but some CD units need a chip changed every so many 1000's of hours. My UV bulb is rated at 9,000 hours, another unit I'm looking at is 20,000 hours. The useless product info - see above.

"I also think that putting an Ozonator on a spa that doesnt run 24/7 is worthless, since it only lasts about 20 minutes." - Ozone in a spa only lasts about 20 seconds, not 20 minutes. I would also venture to say that many people don't use ozone 24/7, all tubs without circ pumps and have ozone operate this way. Also, based on what I've said before and knowing that ozone only lasts 20 seconds - how effective can it really be. If it doesn't bump into someting, it won't do anything.

"Then those same people think they dont need to add anything else and they end up with a big unsanitized mess" - I agree 100%. I think that if you treat O3 as a an auxillary system and treat the tub chemically as most people do, this will not be an issue.

[Vinny]

What I do know is that you need 250ppm of Ozone for it to be effective.

...

Vinny...... not only pure O2, but also zero moisture content and cooled.

I forgot about the moisture content and didn't know about the cooling.

[Ehizzle]

Sorry Vinny,
I'm not sure how much of the 600-900ppm is actually absorbed in the water.

I'm not sure how the grams per hour and ppm convert.

I know that corona chips also need to be changed. I was just using Uv as an example. I'm sure you've experienced the customer that says, "I've had my spa 20 years and the Ozonator light still works"

I wasn't trying to make blatent inarguable statements. My whole point is to get feedback. Thats why I started this post. The 250ppm number I got is from Hot Spring. I don't know where they got that number, but I have never seen them state a fact that wasnt factual when it comes to this kinda stuff. You may dissagree Im just saying what I know. Or, think I know.

[Vinny]

Ehizzle,

No need to apologize! I am just a nerdie techie on this forum, not a spa professional.

I thought I remembered you being a spa professional but I wasn't sure. I personally am on the negative side of ozonation, not to say it doesn't do anything but I don't think it does much. I also know that my ozonator doesn't produce much ozone not because it's UV but the company's ozonators don't produce much ozone.

My view on spa ozoation may change once I replace it with a stonger unit but that's down the road. I only use ozone 8 hours a day and have had it on for 24 hours a day and didn't see much difference. My thought on it (and it could be wrong) is after I soak at night and add chlorine I have the ozonator kick on and do it's thing for 4 hours, 12 hours later it does it again. If it is as strong as proponents say it is then it's killing any nasties (keeping in mind what I "know" about ozone) during the first on period then oxidizing any nasties that it and chlorine killed 12 hours later. Of course it's not selective like that but that's my thinking. I also think that since it only lasts 20 seconds and it needs to bump into something to be effective - how much of it is going to waste, I would think 90% of it. So instead of having it running 24/7 I run it 8 hours.

[Ehizzle]

Well alot of it does just off-gas. The amount of Ozone that gets mixed in the water has to do with the amount of time its in contact with water and how small the bubble are. Thats why having a mixing chamber of whatever is helpful. The less distance between the ozonator and the outside air, the less Ozone absorbsion. Also the smaller the boubles the better.

[Jacuzzi Jim]

 Ozone is measured in milograms most ozonators are 25mg 50mg ect,ect.

 Jacuzzi for instance offers 35mg,50mg, and for there proclean system we offer a 250mg ozonator.  All in all I dont know how many parts per million that is but I do know its effective.  

 As far as contact with water the longer the contact the better, most manufacturers inject the ozone in via a mazzi injector then directly into the spa which the bubbles float to the surface and get trapped under the cover.
 Jacuzzi runs the warm water out of the heater injects the ozone through a bohls injector, slightly different than a mazzi injector around the back of the spa, back to the front  then into the spa so there is very little off gas.  D-1 is the only one I know of that claims no off gas, Hot springs I am not sure.

 The funny thing with ozone is give the average consumer 1 year with there spa and normal chemicals,after a year you could probably unhook the ozonator with out them knowing and they most likely wouldnt even notice a difference. Some opinions may vary and there is always the guy that would see a difference of course.

 Personally I like ozone used with the nat 2 cartridge and a bit of chlorine after use.  keep it simple and the people will cheer.