Hot Tub Forum
Original => Hot Tub Forum => Topic started by: Vermonter on July 31, 2006, 09:23:17 am
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I have followed, with interest, a few of the recent threads that deal with the general subject of "ozone".
I guess it is appropriate for my first post on this forum to focus on ozone - a topic that I have nearly 30 years of experience with ranging from 3 million gallon per day high purity water systems (semiconductor) to drinking water systems many times that size to table-top carafes treating a liter at a time to hot tubs. Regarding hot tubs, one of my first posts on the rhtubs.com site concerned ozone - and, over the years, there have been several dozen on that site that followed that original post.
For this post, I wanted to not get into specific applications of ozone to hot tubs; what brand does or doesn't have a contactor, etc. Rather, I thought I would go through the basics of ozone - both as an oxidizer and as a sanitizer / disinfectant.
I should say that the following represents my opinion - backed by a considerable amount of experience and actual testing of ozone in hot tubs.
General:
First, ozone, like chlorine and bromine, is both an oxidizer and a sanitizer / disinfectant. Ozone functions first as an oxidant and secondarily as a sanitizer (I will use the term sanitizer vs. disinfectant; while ozone is a disinfectant, its use, in hot tubs, would, under optimum conditions, function as a sanitizer).
Ozone as an Oxidizer:
An oxidizer serves to "oxidize" or break down both organic and inorganic "contaminants" in your spa's water. If you use chlorine, some of the more common contaminants are chloramines - shocking with chlorine or MPS will effectively break down those compounds; theoretically, ozone would do the same. Other contaminants are from body waste (sweat, skin flakes, etc.), natural contaminants (pollen, insects, dust, etc.), contaminants in your water (both organic carbon as well as inorganic species such as iron, manganese, etc.). Oxidation breaks these contaminants down into simpler compounds. In the case of organics, the ultimate breakdown product is likely to be carbon dioxide or some simple form of organic acid. In the case of inorganics, it will be some oxidized form of the inorganic (i.e. a metal oxide).
If you have a tub with an ozonator installed and, if you have some "clear" tubing downstream of the Mazzei injector site, take a look at the tubing after a few weeks or months of use - most likely it will be reddish colored. That is the result of the ozone oxidizing the iron in your water from the reduced, ferrous state to the oxidized, ferric (rust) state. The fact that you see this immediately downstream of you ozonator is a visual representation of what I said above - oxidizers, in this case, ozone, functions first as an oxidizer (hence the color immediately after the ozone is introduced).
Part 2 continues with ozone as a sanitizer....and more!
Best,
Vermonter
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Welcome! It's good to see a post from you here.
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I would like to echo Chas's welcome. You are a legend around here. Thanks for posting.
Bill
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Vermonter
How very nice to see you around again. Its been a long time. Hope life's been treating you well.
tony
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Vermonter
Welcome!!
What a way to start posting here!
Thanks for the info.
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To all - Doc, Chas, Vinny, tony, Bill, Steve, Lori...and others familiar with me from rhtubs.com forum- thanks for the welcome. I expect to be back and forth on both - as time allows.
Nice to hear from all of you.
Vermonter
P.S. Beware the Patriots!!!!!!!
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Wow, this is an honor. We have been refering folks to your chlorine bible at rhtubs for over two years. Thanks so much for stopping by. How did you hear about us?
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Can't wait for part 2!!!!!!!
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Stemay,
"Parts" 1, 2 and 3 were all posted within a few minutes of each other (too long to fit in one post or even two; it was kicked back). Just search for the same "Ozone and hot tubs..." title with different "parts". I guess I should have had all in one thread with the second and third being my own "replies". Next time...
Vermonter
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So, what about the claims of Nature2, ozone and MPS being a sanitizing system using chlorine only at start up? Now EPA registered.
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If you have a tub with an ozonator installed and, if you have some "clear" tubing downstream of the Mazzei injector site, take a look at the tubing after a few weeks or months of use - most likely it will be reddish colored.
Vermonter
(http://i20.photobucket.com/albums/b206/EastTexasSpa/DSC01709.jpg)
For illustrative purposes in this highly informative post.
Terminator
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So, what about the claims of Nature2, ozone and MPS being a sanitizing system using chlorine only at start up? Now EPA registered.
HTD,
Before we get into a more general discussion, do you know if Nature2 for Spas is EPA registered or is just Nature2 for pools? If the spa version is, do you have a reference or link - or an EPA registration #? I did a quick search and only found the pool version (#67712-1).
In some respects, the answer won't matter, but I'm curious as to what is registered and what isn't.
Thanks,
Vermonter
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For illustrative purposes in this highly informative post.
Terminator
Great Photo Terminator!
Nice choice on spas - looks familiar! I would guess you are on well water, but, depending on how old your spa is, perhaps not. Were the pumps on when you took this picture?
Check out (unscrew) the diffuser plate for the heater return / ozonator line in the bottom of your tub. You will probably see some discoloration there, although much, much less than what you see on the tubing. This is another "visual" indication that most of the action of any ozone produced doesn't make it to the end of the "contact chamber" much less the tub itself.
Thanks,
Vermonter
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EPA Establishment No. 067712-FL-001
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Hey Andy,
I want to buy a PWC. I want a fast one - I'm watching Craigslist, Ebay and local papers. Know of any good deals?
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EPA Establishment No. 067712-FL-001
Thanks Doc!
I found it under EPA Registration # 67712-15 as well. Not sure why the FL incorporation; it doen't seem to carry through.
Do you happen to have any reference as to the study design / testing parameters EPA uses for their validation?
Thanks,
Vermonter
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Hey Andy,
I want to buy a PWC. I want a fast one - I'm watching Craigslist, Ebay and local papers. Know of any good deals?
Ebay tends to always be overpriced. Craigslist, at least in my area, is "usually" WAY overpriced. Frequently people are asking 2 to 3 times blue book! However, all the one's I've owned, I've gotten off Craigslist. Usually takes a week or 2 to find one. I have to check about 10 times a day (you can bookmark a search) and carry around a wad of cash to jump on the occational deal. Local newspapers aren't a bad place to look either. Also, and local repair shops might have a buliton board for people to post skis for sale. Again though, be prepared to jump on something fast.
I like using http://www.nadaguides.com for general pricing. Prices can REALLY vary in different parts of the country. If I could find a cheap way to ship them from FL to me I could make a small fortune :-)
Any idea what you're lookig for, other than "fast" (and what are you considering fast)?
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HI Vermoneter,
and btw, thanks. I use your method to keep my tub clean. I apprecaite your help. thansk for making my tub easier to enjoy.
I haven't read through all your posts on Ozone, but do you have any thoughts on some of the 03 warnings that come up time to time? Mostly I see these warnings in association with the desktop ozinators.
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My tubing is yellow not red. What does that signify?
Thanks,
Bill
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Thanks Doc!
I found it under EPA Registration # 67712-15 as well. Not sure why the FL incorporation; it doen't seem to carry through.
Do you happen to have any reference as to the study design / testing parameters EPA uses for their validation?
Thanks,
Vermonter
I got nothing for you on this one. sorry.
I do however remember something about a loophole that allows nature2 to get EPA registered. Something about the fact that it came preinstalled in a dispenser.
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My tubing is yellow not red. What does that signify?
Thanks,
Bill
That's the color I'm used to seeing as well, kind of a milky yellow. I've never seen that red colored hose before other than in Term's post and I just assumed that spa had a mose or a gerbel sucked into the line.
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My tubing is yellow not red. What does that signify?
Thanks,
Bill
Hi Bill,
I'm not sure. Was the tubing completely clear to begin with and what type of tubing is it (polypropylene, polyethylene, PVC...)? I assume this is downstream of the ozone but not on other sections of the tubing? Some of the "Tygon" type of clear tubing will naturally yellow with age and / or heat, but that doesn't sound like what you are experiencing.
Last questions - what is the source of your makeup water and does your tub water have any color to it (clear glass against a white background)?
Not sure I will be able to help.
Vermonter
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... Now EPA registered.
HTD,
Both the Nature2 pool version (which contains copper and silver) and the spa version (silver alone) are registered. I looked at the EPA's "Registration Requirements for Antimicrobial Pesticides" as well as a couple of other sources and it appears (to me) that the basic test methods used for submitting data to achieve "pesticide" registration are based on some of the AOAC methods, such as what is called the Use Dilution Test.
I'm somehat familiar with these tests and, in my opinion, if "registration" is based on these, then I do not believe those are adequate for evaluating effeciacy in hot tubs.
In my lab / company we have performed hundreds of microbial challenge studies on a wide variety of water types and appliations. In these "challenge studies" we test how effective a product is against either a specific microorganism or against a range of organisms. While we base study design on client requets (in some cases), in many instances we generate what we believe to be a optimal challenge test - even if it conflicts with "standard" protocols. Depending on how the study design is set up, a single product can pass with great success or fail miserably.
Testing of the efficacy of an antimicrobial treatment in hot tubs requires, in my opinion, a real-world approach. This would incorporate testing over an extended period of time, use of either "real" (human) or synthetic "waste" to represent typical use of a hot tub, deliberate adjustment of pH and other chemistries to cover the range normally encountered by the hot tub population, challenges with specific organisms (ideally, both bacterial and viral), etc. The AOAC test does not do this; neither does the spa "industry Bible" - NSF 50.
My own, admittedly personal, test of using only N2 and ozone (detailed in another recent post) failed to control microbial populations in my tub. Populations skyrocketed to a total of approximately 10 to the 12th power (1, followed by 12 "0's" for total bacteria (heterotrophic plate count).
As I will post on at some point, I do think that Nature2 (ions in general) function very, very well as a secondary barrier to microbial growth once an effective primary sanitizer has been used (such as dichlor).
Vermonter
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Great Photo Terminator! [glb]Thank you kindly[/glb]
Nice choice on spas - looks familiar! I would guess you are on well water, but, depending on how old your spa is, perhaps not. Were the pumps on when you took this picture?[glb]This was a Sovereign we had at an offsite event. The Longview FD filled the spas from a crusty old fire hydrant. The water looked like tea. After one hour of the exclusive 100% No-bypass Filtration, the water was crystal clear. The picture was taken of the spa sitting empty in my store. It has since been sold.[/glb]
Vermonter
This was the exact spa in use at the Alley Fest. Drewstar's niece is the one on the left.
(http://i20.photobucket.com/albums/b206/EastTexasSpa/DSC01595.jpg)
Terminator
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Terminator and East_TX_Spa,
Interesting information. I am a 100% believer in the 100% no-bypass system of HS. If I had to pick one factor that I would rank above nearly all other factors in considering a spa, the type of filtration would rank up very, very high.
A couple of observations...
1) The rusty old hydrant filling would account for particulate iron that would, indeed, be mostly filtered out by the HS filters.
2) That same "rust" would not account for the discoloration of the tubing unless ozone was involved. As evidence of this, look at the tubing on the inlet to the circ pump as well as any of the other sections of tubing that are shown. The only one that is "reddish-brown" is the section immediately downstream of the ozone injection device.
3) So, in addition to the "colored" water used to fill the tub, there had to be a fair bit of soluble iron (iron in the reduced chemical state) that, after ozonation, was oxidized to form the sticky rust-like deposit we see on the ozonator outlet tubing.
4) I couldn't tell, but it didn't look like the pumps were on. It looked like there was water in the ozone line feeding the Mazzei (part-way back to the check valve or loop and it appeared that there were some large bubbles in that outlet line as well.
Thanks for the information about the tub fill!
Vermonter
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Terminator and East_TX_Spa,
Interesting information. I am a 100% believer in the 100% no-bypass system of HS. If I had to pick one factor that I would rank above nearly all other factors in considering a spa, the type of filtration would rank up very, very high.
Maybe it one one of Term's famous photoshoped no-bypass diagrams that sold him on it?! LOL
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Vermonter,
Sorry for the delay in reply. Had to go look at the thing which is at home, whereas I participate here from work. First of all, I am just curious, really don't think the color of the tubing is important. Anyway here goes:
"Was the tubing completely clear to begin with and what type of tubing is it (polypropylene, polyethylene, PVC...)?"
The tubing is completely clear when new. The dealer says the tubing is whatever HS uses, but he is not sure what it is and I couldn't find any label or printing to help. My assumption is PVC.
"I assume this is downstream of the ozone but not on other sections of the tubing?"
That is correct.
"Some of the "Tygon" type of clear tubing will naturally yellow with age and / or heat, but that doesn't sound like what you are experiencing."
No I don't think so either. It might have something to do with the local water. Our municipal supply comes from deep underground wells. Florida is based on limestone down deep with sand near the surface. The HS dealer says the yellow color is normal for this area.
"Last questions - what is the source of your makeup water and does your tub water have any color to it (clear glass against a white background)?"
All of the water is supplied by the municipality where I live (Wellington, FL). I use a HS Pre-filter for it. It is clear but quite green before treatment. If it would help, I can get the water people to send me the analysis.
BTW, just so you know, I am a CE, but not a water guy. I follow your water treatment program and can give you the breakdown on the initial chemical additions if it would help.
Regards,
Bill