Hot Tub Forum
Original => Hot Tub Forum => Topic started by: soon2float on June 30, 2004, 10:12:18 am
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We are looking for a tub about 8' square with 1 lounge, in the 5-6500 range.
Several we have looked at have the circ pump as an option or not at all. Does anyone know if it truly is a savings.
We have looked at Artesian, LA Spa Heet, and Coast. Any other recommendation are very welcomed.
Thank you so much,
Lisa
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Both methods are fine for filtering but when comparing the two I like the circ pump idea for other reasons. It is a bit of a cost saver (not major) but more importanatly to me, it allows for 24 hr ozone and is much quieter.
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Spa Tech,
Thanks for answering. Why is 24hr ozone any more effective than the regular pump occassionally running keeping up temp running through the ozone filter?
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Why is 24hr ozone any more effective than the regular pump occassionally running keeping up temp running through the ozone filter?
Circ pumps run 24/7 and therefore you're getting ozone mixed with the water 24/7. With a 2 speed pump you're getting ozone during the filter/heat cycles (plus any time you're in it with the pumps on) which typically equates to about 6-8 hrs per day. Therefore, you're getting ozone input into a spa with a 24 hr circ pump about 3-4 times more often than a spa without a circ pump. I'm not saying this should disallow any thoughts of getting a spa without a circ pump but it is a big positive on the circ pump side.
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When I was shopping, the Marquis dealer made a very effective arguement for using the main pump in lieu of a small 24-hour circ pump. Marquis apparently did offer the 24-hour pumps for a few years and then changed to their current design. The main reason was that the 24-hour pumps only last for a few years before they fail.
On the plus side, the 24-hour pumps offer constant ozone, even heat distribution, and clean water at all times.
In the end I concluded that how the pumps are configured ranks along side of horsepower ratings and the number of jets. In the final analysis all not very important relative to the more important issues of reliability, ergonomics, ease of use, and so on.
Regards,
Bill
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As Bill mentioned each have their merits....the biggest problem with the circ pump being the lower volume of water they move on a daily basis....around ten times a day or so where using the low speed of the larger pump will allow you to turn over your water closer to 60 times a day....but both seem to work fine....and each offers advantages over the other.....
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The neverending debate over circ pump "advantages"...
You'll most likely find, as I have, through long research that there are folks who swear by the advantages and savings of the 24/7 circ pump and pretty much an equal number of others who say that it's basically just an additional cost that needs replacing. Yes, filtration is occuring all the time but often times the quantity of water filtered over a 24 hour period is less than tubs without them. Ultimately I don't think it should be a deciding factor when choosing a tub.
As for ozonation, I've found that it's simply not been around long enough in spas to offer any reliable data. I have been unsuccessful at finding any concrete answers to many questions regarding spa ozonators such as "what is the empirical advantage of having an ozonator in a spa" and "is there a real advantage to having ozone introduced into your water more often". Other factors involved in its "effectiveness" include ozone concentration, length of contact chamber and time spent in the contact chamber.
I have concluded that there is not enough data regarding spa ozonators to make a big difference in my spa decision but I will most likely get one to gather some data of my own.
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Both methods are fine for filtering but when comparing the two I like the circ pump idea for other reasons. It is a bit of a cost saver (not major) but more importanatly to me, it allows for 24 hr ozone and is much quieter.
I agree with the above.
Have a look at Beachcomber, Marquis and Dimension One
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Or you could look at a spa that does both...circ pump and filter cycles...such as sundance/jacuzzi premium.
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That's how ours is. We have the 24 hour circ pump, and can also set the main pumps to cycle on and off at will for more agressive filtering.
Have not had our spa long enough to comment on the longevity of the circ. pump.
Brewman
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They all do this. The little circulation pumps do not move enough water to prevent stagnant areas. Specifacly in the corners. The primary pumps in most of these spas will automaticaly come on for 20 or 30 minutest 3 or 4 times a day to do a big stir up. Even the HotSprin Spas have what they call the clean up cycle. You are supposed to press this button after spa use. All it's doing is turning on the main pumps to get the water sufficiently filtered. To me, this says, circ pumps are an unneeded expense. My spa is a 2000 Jacuzzi Laser Select. No circ pump, with an ozonater. Jacuzzi spas disable the ozonater for 2 hours when any button is pushed so ozone will not be released into the spa while it's in use. It's automatic filtration time is 2 hours 2x a day and the water is always crystal clear and smells nice! Circ pumps are a nice sounding sales tool that sounds like "folks, this spa is so automatic it filters your water every day all day and you don't have to do a thing".
Or you could look at a spa that does both...circ pump and filter cycles...such as sundance/jacuzzi premium.
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Thank you all for your help.
Wisoki, In all my searching I have not heard of any tub turning off the ozone during use (not to say they do not do this, but no one ever mentioned it. Is this important and should I look into this further.
Thanks again
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It's important because ozone is a toxic gas that can be harmful over prolonged periods of exposure.
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It's important because ozone is a toxic gas that can be harmful over prolonged periods of exposure.
Kinda makes one wonder why it would be advantageous to have ozone introduced via a 24/7 circ pump...
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I'm not sure of others, but SD spas turn ozone off when any main pumps are on.
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Kinda makes one wonder why it would be advantageous to have ozone introduced via a 24/7 circ pump...
I'm not sure I understand the question as even those who are prefer a 2-speed pump will typically agree that the idea of 24/7 ozone is an advantage of a circ pump. Ozone has no residual, meaning as soon as it’s turned off there is none available, so you want it working as much as possible. In fact, when people with a 2-speed pump want to lower the amount of time the pump is on for filtering I always explain to them that there is a tradeoff as the more they lessen their filtering, the more they lessen the amount of time the ozone is on.
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I'm not sure I understand the question as even those who are prefer a 2-speed pump will typically agree that the idea of 24/7 ozone is an advantage of a circ pump.
Not really a specific question, I just continue to search for answers.
In this case my question would be: why is 24/7 ozone an advantage??
Athough ozone may have no residual (if it did it could be more effective), it needs to be aqueous ("disolved" - not in bubbles) to be effective. I'd like to see some empirical data to support that 24/7 circ pump ozonation is more effective. From what I've seen, at the concentrations that aqueous ozone is introduced into any spa it appears as though the amount of time ozone is introduced is irrelevant. Similar to the take on filtering, 24/7 circ pump is filtering much less water over a longer period of time than the periodic jet pump circ in a shorter period - it's volume not amount of time, where the effectiveness of ozone remains to be seen.
The only sound data I've come across is that the more you have the ozonator running the more often you'll have to maintain it and the more often you'll need to replace it. Also, a most important factor is the system's success in making the ozone usable, in aqueous form; that is in part done by length of time the ozone spends in the contact chamber before it is released into the tub to bubble up to the surface and just add to the air (by the way, careful when you open that cover - you just may get a blast of ozone... hmm is that bad? that lead me to another question, is 24/7 circ ozonation adding more ozone to the air under your cover?).
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What you need is to mix the ozone with the water as long as possible before it reaches the top surface of the water. A good tub has a contact chamber that may be about 10 feet or so giving the ozone more chance to mix and do its job. Ozone is being drawn thought the tube and into the tub about 6-8 hrs a day for spa with a 2-speed pump and for 24 hrs a day for spas with a circ pump. The fact that the ozone is being input into the chamber for the additional 16 hrs or so is why a circ pump is absolutely an advantage relative to ozone (and I'm only speaking relative to ozone).
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Spa tech....
I understand what you are saying about the 24 hour of ozone using the circ pump but if you are moving the water volume in the spa around ten times daily where with the 2 speed pump closer to 60 times even if it is getting ozone only 4 to 8 hours a day the total volume of water would still be more ozone enriched so to speak....as you are filtering more volume...am I wrong to think this....
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The fact that the ozone is being input into the chamber for the additional 16 hrs or so is why a circ pump is absolutely an advantage relative to ozone (and I'm only speaking relative to ozone).
It certainly is an advantage relative to *using* the ozonator more... but again, it is not evidence that it is more effective or "better" relative to sanitizing your spa.
Length of contact chamber does play a small part (as well as other factors) in effectiveness - is a circ pump with a 5 ft chamber better than a jet pump with 25ft? I'm not saying that circ pump ozonation is not advantageous (I don't know, but am interested to find out), I'm just saying that there is no concrete evidence to suggest that it is; just because it's fact that the ozonator is running over a longer period of time does not mean that it is more effective. Just as saying 24/7 circulation alone doesn't mean that it's more effective at filtering.
Mendo, no, you are not wrong to think that way.
It *may* not be an accurate assumption but then again you may be right on. How much effective ozone is each method introducing into the tub? How does volume and velocity of movement effect the effectiveness of a spa ozonator? And again considering the concentrations of aqueous ozone in any spa, does any of the differences matter?
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OK, I have ready most of this post and now have to pipe up a bit. Here is the reasoning as far as I understrand:
1. Filtering vs. Ozone - Two different functions. Filtering is a function to remove particulate from the water. So yes, most tubs with circ. pump and ozone will cycle, even if only for 30 seconds x 2-3 times daily, to remove the particals/sediment from the water via the filter. Ozone's only function is to act as an oxidizer and kill organic matter. Hence, two very seperate functions.
2. Circ. Pump vs. Intermitten Main Pump - Ozone has a half life of approx 20-40 minutes if I am not mistaken. Ozone is VERY short lasting and must be produced on an ongoing basis, hence the lower chemical concentration (bromine, chlorine etc) of 0.5-1 ppm. If the ozonator only turns on every four to 12 hours (or whatever you may have scheduled), you will be essentially running without your main disinfectant for most of the time between cycles, relying on your lower concentration of chemical, which is only intended as a back-up system.
Bottom Line - If you are using Ozone, you should have a 24/7 Circ pump, or else up your chemical concentration, which defeats the purpose of Ozone!
Hope this all makes sense!
OnMedic
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Empo,
Certainly you must first be a believer in ozone in order to buy into the fact that the increased ozonation from a 24/7 circ pump is beneficial. IF you are a believer (as my experiences have made me) then a 24/7 circ pump will provide more ozone and do the job better for you. If you are not a believer then you don't care and will save the money by never having an ozonator installed the first place.
Mendo,
A 2-speed pump may give you 5 times the filtering by moving that much more water (or whatever the number may be) but it doesn’t provide 5 times the ozone and over the course of the day you get much more ozonation from a circ pump. Good question but it doesn't work that way.
BTW, you're supposed to believe anything I say as after all, I have Ultimate Member status. Only 796 more posts to get to 1000 to make me a Grand Poobah Member. In reality, I'm not saying you should get a spa with a circ pump because of the increased ozone alone. I was merely responding to the original post relative to how a circ pump benefits you and ozonation is one of them. If you've got a spa with a 2-speed pump or are more a believer in that method then more power to you.
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Makes sense OnMedic - thanks!
But I'm not convinced of your bottom line.
Do you have any data to support the need to up your concentration of chems soley based on jet pump ozonator versus circ pump? What is the ozone concentration in the tub of a low flow circ pump versus a higher flow jet pump? Seems to me that Mendocino101 is onto something with the volume idea - it's a race to move that ozone into as much of the water as possible to do its dirty work before it decays.
Hadn't considered the half-life aspect before...
If half-life is 20-40 minutes that would mean that it's potentially around for several hours before it's gone depending on how much you got in there (half-life is the amount of time for half of the ozone to revert to O2: for example, after 40-80 minutes you would still have 25% of your ozone) which would make the difference of how often the ozone is introduced moot. Though I'd imagine ozone half-life is much shorter in a 100+ degree spa, probably around 3-5 minutes depending on the rest of the water's chemistry - meaning it is indeed a race to move it around before it's gone.
2 approches to the same end result??
- Constant ozonation at low volume (water movement)
- Periodic ozonation at a significantly higher volume
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2 approches to the same end result??
- Constant ozonation at low volume (water movement)
- Periodic ozonation at a significantly higher volume
That's where the misconception comes in. Even though you're getting more flow with the 2-speed pump than the circ pump you're not getting more ozone and you really don't want more as all you'll do is have a big off-gas problem. A spa with a circ pump uses a different injector than one with a 2-speed pump as the orifice size has to change to compensate for flow.
Bottom line, you get much more ozone mixed with the water in a spa with a 24/7 circ pump.
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Certainly you must first be a believer in ozone in order to buy into the fact that the increased ozonation from a 24/7 circ pump is beneficial. IF you are a believer (as my experiences have made me) then a 24/7 circ pump will provide more ozone and do the job better for you.
Oh I am a believer in ozone - it's just that the answers as to why it's more effective in 24/7 circ pump has not convinced me to believe it. Give me the data to support the bottom line.
My conclusion thus far is that there is no data to support which is more effective either way. If the particular tub has its system designed effectively it makes no relevant difference if it's done with a circ pump or jet pump.
But hey, I'm still learnin', I'm only a full member :)
Thanks so much for your input, I've learned a lot on this thread.
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As far as we all know now, this is probably a non issue. Buy a top 6 brand and you'll be ok...
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Well the 24 hour circulation pump moves water through the chamber more slowly. If a 24/7 pump moves the contents of the tub 10 times a day and intermitent jet pumps move the contents of the tub 60 times a day, then:
1) If the contact chambers are equal
2) If the ozone output is equal
then the water in the contact chamber of a tub with 24/7 pump gets 6 times the contact time than another tub.
To even this out, either:
1) The contact chamber of intermitent, larger pump systems must be 6 times longer or
2) The ozonator in such systems must put out 6 times the ozone.
Am I missing somthing, because this seems obvious to me? :-[ Anyway, that's why I've always felt that a 24/7 slower pump is better for ozonation.
If the water is shooting through the chamber 6 times faster it will be in the contact chamber 1/6 of the time of a slower pump. When talking about a fixed sanitation method you want water to go as slow as possible by the sanitation method for maximum benefit, to stay in contact with that sanitation method for as long as possible. Great for sanitation, less great for filtration (which is optimized by maximizing the number of passes through the filter)
-Ed
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Well the 24 hour circulation pump moves water through the chamber more slowly. If a 24/7 pump moves the contents of the tub 10 times a day and intermitent jet pumps move the contents of the tub 60 times a day, then:
1) If the contact chambers are equal
2) If the ozone output is equal
then the water in the contact chamber of a tub with 24/7 pump gets 6 times the contact time than another tub.
To even this out, either:
1) The contact chamber of intermitent, larger pump systems must be 6 times longer or
2) The ozonator in such systems must put out 6 times the ozone.
Am I missing somthing, because this seems obvious to me? :-[ Anyway, that's why I've always felt that a 24/7 slower pump is better for ozonation.
If the water is shooting through the chamber 6 times faster it will be in the contact chamber 1/6 of the time of a slower pump. When talking about a fixed sanitation method you want water to go as slow as possible by the sanitation method for maximum benefit, to stay in contact with that sanitation method for as long as possible. Great for sanitation, less great for filtration (which is optimized by maximizing the number of passes through the filter)
-Ed
Ed great analysis.
Some manufactures using a circ pump have contact chambers of 6 feet.
I have seen Mfg without circ pumps using up to 25 foot contact chambers.
I have never seen specs on the output of ozone on various makes nor the differences between UV, cd chip, and plasma cell, relative to their output.
I am interested in the new plasma cell type to see if it will last, maintanence free for 6 - 7 years and its cost compared to the other two systems.
I guess time will tell.
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I also like the fact that I heat through the circ pump....quiet and efficient....main pump doesn't have to come on every time the heater does.
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I think you are greatly overstating the "half life" of ozone, to my knowledge it is 20 to 40 seconds. Since it doesn't become a liquid and mix with the water, but is a gas that very quickly raises out of the water, regardless of "contact chamber" and forms a gaseous layer between the cover and water surface. Ozone should NEVER be considered a "Primary" sanitizer. It is has and always will be a suplimental system to bromine, chlorine or biguanides. Even when used in conjunction with a mineral purifier i.e. N2, spa frog, etc... it is secondary to the table spoon per 100 gallons of chlorine and regular addition of shock.
2. Circ. Pump vs. Intermitten Main Pump - Ozone has a half life of approx 20-40 minutes if I am not mistaken. Ozone is VERY short lasting and must be produced on an ongoing basis, hence the lower chemical concentration (bromine, chlorine etc) of 0.5-1 ppm. If the ozonator only turns on every four to 12 hours (or whatever you may have scheduled), you will be essentially running without your main disinfectant for most of the time between cycles, relying on your lower concentration of chemical, which is only intended as a back-up system.
OnMedic
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Incorrect, the exact same mazi injector is used.
That's where the misconception comes in. Even though you're getting more flow with the 2-speed pump than the circ pump you're not getting more ozone and you really don't want more as all you'll do is have a big off-gas problem. A spa with a circ pump uses a different injector than one with a 2-speed pump as the orifice size has to change to compensate for flow.
Bottom line, you get much more ozone mixed with the water in a spa with a 24/7 circ pump.
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Incorrect, the exact same mazi injector is used.
Actually it is correct, as there are different colored Mazzi injectors out there. The colors denote the orifice size at the intake as the flow difference between a circ pump and a 2-speed pump creates varying venturis therefore requiring a different orifice size to control he amount of ozone being drawn in. If you're only dealing with 2-speed pumps you probably only use one type but a circ pump does require a different mazzi than a 2-speed pump if you want to match the systems properly.
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Well the 24 hour circulation pump moves water through the chamber more slowly. If a 24/7 pump moves the contents of the tub 10 times a day and intermitent jet pumps move the contents of the tub 60 times a day, then:
1) If the contact chambers are equal
2) If the ozone output is equal
then the water in the contact chamber of a tub with 24/7 pump gets 6 times the contact time than another tub.
I think you meant to say 6 times less, no?
If the water is shooting through the chamber 6 times faster it will be in the contact chamber 1/6 of the time of a slower pump.
The big assumption with this analysis is that all of the water moved through the jet pump moves through the ozonator chamber. This is wrong. For example, with one system I am familiar (through obsevation of equipment), water coming from the filters through the pump gets diverted into 2 directions, ~ 1 1/2 inch pipe to the heater and ~ 1/2 inch tube to the contact chamber, so somewhere around 1/8 of the water flows through the contact chamber.
The question/consideration of volume and water movement with respect to ozonation effectiveness would mostly apply to the off-gas coming out of the ozonator jet. The greater the water movement in the tub the greater the chance of putting it to use before it reaches the surface.
As I've said before with the legal concentration of ozone allowed in any spa the differences between the two methods are probably insignificant. As Zz concurred, no specs, no data... only time will tell.
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The question/consideration of volume and water movement with respect to ozonation effectiveness would mostly apply to the off-gas coming out of the ozonator jet. The greater the water movement in the tub the greater the chance of putting it to use before it reaches the surface.
As I've said before with the legal concentration of ozone allowed in any spa the differences between the two methods are probably insignificant. As Zz concurred, no specs, no data... only time will tell.
First off, I know of NO hard data on ozone performance in spas, so we're all really guessing at this point. Let me correct one misconception-- bubbles are NOT dissolved (aqueous) ozone and are therefore irrelevant to discussions about oxidizing/sanitizing. My take, as someone who has done a fair amount of lab chemistry work: you'd want a continuous injection of ozone with a flow rate slow enough to ensure:good contact chamber time and minimization of turbulance and high-speed impacts with nucleating material that would cause the ozone to outgas from solution. Think of pouring a soda quickly over ice and how much foam is created. Even if the ozone stays in solution when you move the water quickly, you would effectively be diluting the ozone in a greater volume of water. You won't find many pathogens in a teaspoon of straight bleach, but dilute that tablespoon in a spa and its sanitizing power is lost. Because the half-life of ozone is so short and the rate of ozone production relatively low compared to water volume, any dissolved ozone would rapidly be depleted from the water and therefore the water will continuously be capable of accepting more ozone. If additional ozone is not continuously supplied, you aren't taking full advantage of the ozonator. Some assumptions I've made:
1. Ozone is actually oxidizing and/or sanitizing in meaningful amounts
2. Demand for ozone always exceeds supply
3. Ozone is produced at a fixed rate
Until someone does some good studies on use of ozone in spas, how an ozonator is best used will come down to personal belief.
Starlight
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Starlite,
I appreciate your comments. Are you saying that for example that if you are using a high flow system.( 2 speed pump) and moving more water but doing so with an adequate contact chamber say 20 ft or greater than it is effective ? or are you saying that for spa use the slower moving circ pumps does offer better ozone zanitation....or that both are truly still up for debate as to which is significantly more effective.
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First off, I know of NO hard data on ozone performance in spas, so we're all really guessing at this point....
Until someone does some good studies on use of ozone in spas, how an ozonator is best used will come down to personal belief.
Thank you for your input Starlight!!
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... for example that if you are using a high flow system.( 2 speed pump) and moving more water but doing so with an adequate contact chamber say 20 ft or greater than it is effective ? or are you saying that for spa use the slower moving circ pumps does offer better ozone zanitation....
Mendo keep in mind that the flow through the chamber in a 2 speed pump system is not such "high flow" because only a portion of the flow gets diverted to the chamber.
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Mendo keep in mind that the flow through the chamber in a 2 speed pump system is not such "high flow" because only a portion of the flow gets diverted to the chamber.
Are you saying this is true of all makers, using the "hi flow" system....I do not know the answer...just wondered...I just spoke with a friend of mine who shared with me that in his opinion Ozone works great for the single guy or couple that travels or uses the tub more lightly....and does offer some real benefits in the aid of zanatioan.....but for a family who uses the tub alot...its effectiveness is much less benifical...
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Are you saying this is true of all makers, using the "hi flow" system....
Nope - I sure ain't, but considering all the great insight gleaned from this thread I sure wouldn't consider one that doesn't.
Whether that's the case or not for a particular tub is a critical question for those who care about what they are paying for.
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I think you meant to say 6 times less, no?
No. That was the point. It's 6 times more because it is moving 6 times slower. The slower you move past something, the longer you are in contact with it.
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Mendo keep in mind that the flow through the chamber in a 2 speed pump system is not such "high flow" because only a portion of the flow gets diverted to the chamber.
I think he meant compared to a less powerful 24/7 pump. Or are you saying that a 24/7 dedicated circulation pump actually moves more water through a contact chamber than tubs which use the jet pump?
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On tubs with a 24/7 circulation pump is it guaranteed that all water being pulled from that pump is going through the contact chamber?
Empolgation stated that in at least one brand of tub only 1/8 of the water pulled from the pump on clean cycle is going through the contact chamber.
On the assumption that:
1) a spa has x gallons of water
2) a 24/7 pump moves 10X a day
3) a 24/7 pump has all of its water going through the contact chamber.
4) a jet pump on clean cycle moved 60X a day
5) 1/8 of the water on a jet pump clean cycle goes through the contact chamber
then a tub with a 24/7 pump moves 10X of water through the contact chamber
And a tub with a jet pump moves 60X / 8 of water through the contact chamber, or 7.5X.
Even though the jet pump method moves less water past, I am assuming it still moves the water at a faster speed than the 24/7 pump water. Is that correct?
Can some actual hot tub techs chime in on some other brands of tubs and how they feed the contact chamber?
Also, I think that we assume that ozone is somehow evenly distributed throughout the chamber. It that true? Is ozone injected across the whole 20'? It seems like the shorter the contact chamber the easier it is to get a more uniform distribution of ozone.
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Starlite,
I appreciate your comments. Are you saying that for example that if you are using a high flow system.( 2 speed pump) and moving more water but doing so with an adequate contact chamber say 20 ft or greater than it is effective ? or are you saying that for spa use the slower moving circ pumps does offer better ozone zanitation....or that both are truly still up for debate as to which is significantly more effective.
As I said earlier, we really don't know. But, my a.s.s.umption (software altering word unless I added periods) is that the actual amount of ozone produced is the real limiting factor. If true, it really wouldn't matter how that ozone was dissolved into the water(hi/low speed, large/small contact chamber) as long as both methods dissolved equal amounts into the water. The actual effects of the ozone (because of its short lifetime) would probably only be observed in a small "slug" of water that is in the contact tube and near where ozone is introduced into the tub. As emplogation points out, just because your pumps move more water doesn't mean that you are moving that water through the ozone system. If you *could* move that water through the contact chamber AND if it resulted in a higher percentage of gaseous ozone dissolving into the water, then there could be advantages to that type of setup. The other thing we don't know is if ozone from this generation of systems is effective as a sanitizer. If it is, then you'd want ozone 24/7 to help kill the reproducing bacteria; if it isn't, then all ozone does is burn up other organic matter and as long as your "slow & continuous" and "fast & concentrated" systems both delivered and made effective use of the same quantities of ozone, they'd be equivalent.
Your friend's point about the effectiveness of ozone suggests that the amount of ozone generated--or at least the ammount able to be dissolved into the water--is the limiting factor. If the current ozone systems can oxidize the equivalent of "4 user-hours" per day of body oils, etc., one would find the most dramatic reduction of spa sanitizer demand in a spa where the spa usage fell at or below "4 user-hours"--one person for four hours, two people for 2 hours, etc. If the whole family uses the tub, then the ozone is still taking care of its "four user-hours" of stuff, it just isn't as apparent when the demand is for a much higher "user-hours" of stuff introduced into the spa.
Starlight
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On tubs with a 24/7 circulation pump is it guaranteed that all water being pulled from that pump is going through the contact chamber?
Yes.
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Wow, I cannot believe the controversy this topic created. It seems the only agreeable conclusion here, by so many of you who I would feel are experts on tubs, is that there does not seem to be any documentable proof as to the actual effectiveness of Ozone in hot tubs.
Logically, one would assume that Ozone has some beneficial effect in hot tubs or companies would not want to increase their cost of a tub, so studies must be available some where. Are there any chemical engineers out there who are aware of any research papers written on the subject that might help us resolve these questions here?
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Shortly after I posted my last comment I received this article. ( I have to cut it in half to fit in this forum)
Ozone Eliminates E.Coli Bacteria
By Paulette Scoville
Ozone gas is extremely effective for controlling bacteria and virus contamination. It has been used quite successfully in Europe for the purification of drinking and recreational water since the 1800's and is not harmful. Until fairly recently, the purity of water and food products in the United State has usually been assured by the addition of chlorine to kill dangerous microorganisms.
There's no doubt that chlorine and chlorine gas can be effective. In fact, chlorine gas was utilized during World War I killing not only bacteria and viruses, but several hundreds of thousands of young men as well. Throughout Europe, families saw the effects of this deadly gas and did not desire to use it in everyday living. Instead, they worked to develop an environmentally safe and user-friendly form of water purification. A system that imitated "cleansing, refreshing" reactions in nature. The result: The development and application of ozone generators.
For years the standard solution for water purification in the United States has been chlorine or other chemicals. As early as the 1920's chlorine has been used in many public systems to disinfect drinking water. To this day, chlorine is used regularly to sanitize drinking water as well as swimming pool and spa water. The by-products of chlorine are not pleasing to the taste and can irritate our skin and eyes in pools and spas as well as in the shower or bath tub.
But the quick solution is not always the best solution. In fact, the application of chemicals for water purification and food treatment has been determined to be a misnomer contributing to health problems. For example, within the last ten years, studies have shown that chlorine can produce undesirable by-products - among them trihalomethanes. Trihalomethanes are carcinogenic.
Until many of the problems linked with chlorination were discovered, ozonation had been virtually unused for potable drinking water in the United States. Currently, there is a growing trend in the food and beverage industry to utilize ozone in product preservation and quality assurance. In Title 21 of the Code of Federal Regulations (CFR) ozone is affirmed as generally recognized as safe (GRAS) for use as an antimicrobial agent in the treatment of potable water for bottling. (It is the leading method of water treatment used by bottling plants). In addition, ozone is prior sanctioned under the Meat Inspection Act for use in meat aging coolers under a restriction that ozone-generating equipment is operated in a manner which will not result in more than .01 part per million (ppm) of ozone in the air and is shut off for definite periods as required for inspection of the meat coolers. Further, under EPA's jurisdiction, ozone is used to treat municipal water systems.1
Ozone is often called "active oxygen". It is naturally produced in the Earth's upper atmosphere when sunlight passes through the air. For applications to water purification, ozone is most commonly produced by passing air past an ultraviolet light in a sealed chamber. The then ozone-rich air is discharged into the pool, spa or potable water through dispersion heads as it circulates through an existing filtration system. The first observations mentioning ozone's disinfecting property for drinking water date back to the end of the last century. In 1886, De Merites noted a reduction in levels of microorganisms after ozonation. A significant amount of research, both fundamental and applied, has since confirmed his initial findings. Among the most important works are those done by Katzelson in Israel, Sproul and Majumdar in the United States.
Ozone's destructive action on microorganisms in water is widely acknowledged, particularly on the Escherichi cold (E. coli), Cryptospondium, Poliovirus and Giardia cysts (including Giardia muris and Giardia lamblia). Ozone may be said to act blindly, since no limits to disaffection have been found in the numbers or species eliminated. Such universality may best be explained by the mode of action of ozone: in contrast to the usually employed halogens, ozone does not have a reversible inhibitor effect on intracellular enzymes. Because of its very high oxidation reduction potential, this disinfectant acts as an oxidant of the constituent elements of cell walls before penetrating inside microorganisms and oxidizing certain essential components (e.g., enzymes, proteins, etc.).2 When a large part of the membrane barrier is destroyed, the bacterial or protozoan cells lyse (unbind) resulting in gradual or immediate destruction. By attacking plasmodia, viruses, trophozoids, cysts, spores and/or cellular aggregates ozone can provide an effective barrier to the transmission of diseases given that the ozone is properly applied.3
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Second Part
In 1967, guidelines for ozone disinfection were established based on a series of studies done in 1964 and 1967 by Coin et al. Studies done on the Poliovirus determined that the following ozonation conditions always guaranteed at least 99.99% inactivation of Poliovirus and E. coli:
Establishing a dissolved ozone residual level of 0.3 milligrams per liter.
Maintaining the 0.3 mg/liter dissolved residual level for a minimum of 4 minutes.
For the above mentioned studies, 1 ml of virus suspension was added to 1 liter of water in a specially designed flask. A 5 mg dose of ozone was added to the flask and was inverted and shaken vigorously over the four minute period. Virus titration samples were obtained by diluting the total ozonated sample with a culture medium containing 10% veal serum (to destroy the excess ozone present). Additionally, these
studies showed that each time the value of residual ozone measured in the water was below 0.3 mg/liter, viruses were only partially inactivated after the four or eight minute period of contact time with ozone. The antithesis being residual ozone values for higher than 0.3 mg/liter sufficiently inactivated the virus to below a limit of detectability in less than four minutes of exposure time.7,8
Having established the necessary residual ozone concentration to provide 99.99% viral inactivation as 0.3 mg/liter in the batch studies, these investigators then set up a continuous flow column apparatus. In this apparatus, ozone was applied to virus-containing water samples on a continuous basis. The bubbles of ozone / air rose upward while the water flowed downward through the apparatus. Under these conditions, the ozone content of the water increased in gradual stages until it reached a theoretical maximum corresponding to a balance between the various demands of ozone (dissolving of ozone and release of ozone to the atmosphere, reaction of ozone with demand). Generalizing ozone disinfection was initiated and further experiments with other bacterial and viral germs reaffirmed these conditions were necessary and sufficient.9 Over a fifteen year period of research, ozonation conditions have shown that in normal operation water containing no suspended matter and little oxidizable matter is completely free of pathogenic bacteria after ozonation, according to the most accurate detection methods in use. Consequently, it is safe according to the most accurate detection methods in use. Consequently, it is safe to determine that maintaining a dissolved ozone residual of 0.4 mg/liter (0.1 mg higher than tested) for a minimum of 4 minutes is the rule for obtaining drinking water of high microbial quality.1,10
Unfortunately, the Department of Health and Human Services currently limits ozonation processes to treatment by ozonated air-despite substantial documentation with regard to ozone's effectiveness for purification and elimination of bacteria and viruses in food products. Under Title 21 of the CPR the use of ozonated water in washing produce and food / meal products is not permitted. In order for a retailer or manufacturer to use ozone to wash or spray food products at the retail point of purchase, it is necessary to submit in accord with 21 CFR 171.1, a food additive petition. This petition must supply sufficient information to justify amendment of FDA's regulations to provide for the retailer/manufacturer's proposed use.2 The reasoning: a "safety concern" with the proposed use in the potential formation of ozone byproducts for which they felt safety data are lacking. How many years of research is needed for ozone to be recognized as a safe and viable alternative? More than fifteen years of significant research verifying and reverifying consistency in data and effectiveness of ozone presently exists. Perhaps the problem is not effectiveness of ozone, but rather the hold that chemical companies have on governmental regulations - even to the point of denying a viable alternative exists that can effectively treat food products for deadly viruses (such as E. coli) and save lives.11
At one time, there was an argument that ozone generators were expensive and not a viable method for many to use for purification. This is no longer true today.
Food and Drug Administration; HHS, U.S. Pharmacopeial Convention, Inc.; Rockville MD, P.481 Section 184.1563 Ozone.
Handbook of Ozone Technology and Applications,; Vo/. 11. Ozone for Drinking Water Treatment; Rip G. Rice and Aharan Netzer, Butterworth Publishers, MA; 1984; p.1.
Handbook of Ozone Technology and Applications,; Vo/. 11. Ozone for Drinking Water Treatment; Rip G. Rice and Aharan Netzer, Butterworth Publishers, MA; 1984; p.2.
Schwiz. Heits. Hydrologie; F. B. Sulzer, B. Ramadan and K Wuhmmann.; 1959 2: pg. 112-121.
Water and Wastewater Disinfection With Ozone; Crit. Rev. Environ Control; RN. Kinman; 1975; Volume 5, Illue l; pp. 141-152.
Inactivation par l'Ozone due Vws de la Poliomyelite dans les Euax; la Presse Med; L. Coin, C. Hannoun, C. Gomella and J.C. Trimoreau; 1967; pp. 1883-1884.
Rapid Test for Assay of Ozone Sensibvity in Escherichia coli; Mo. Gen Genet; C. Hamelin and Y.S. Chung; 1976; vol. 145, pp. 191-195.
Ozone in Water Treatment Application and Engineering; Lewis Publisher; Chelsea Ml 1991
Based upon this article, it would appear an ozone concentration of 3-4mg/liter is necessary to achieve the proper cleansing effect. What do you experts think?
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Based upon this article, it would appear an ozone concentration of 3-4mg/liter is necessary to achieve the proper cleansing effect. What do you experts think?
Good article. As this shows, there are data demonstrating the effectiveness of ozone treatment of water, just not water in spas (at least, none I can readily find.) Many studies are done under conditions that are very different from those in a spa, so care must be taken when trying to apply the results of a study to spas. I think you misplaced a decimal; they mention ozone concentrations of 0.4 mg/L or about 2 ppm. A few back of the envelope calculations shows that this is roughly 0.2 cc of pure ozone gas per liter--about one tenth of a teaspoon. This number makes it at least plausible for the spa ozone systems to meet this ozone demand, as opposed to a calculation that showed a requirement for say 1000 times that number which would clearly not be possible from such a small ozonator.
Next, we need to know just how much ozone actually gets produced, then how much dissolves into the water, and how long a certain concentration of ozone remains in the water. One other promising piece of information I found is that ozone has over ten times the solubility of oxygen in water, at least at zero degrees C, so it should be possible to solubilize sufficient quantities with a good injector/chamber design. The reports that no one has succeeded in detecting measurable quantities of ozone in spas suggests to me that it is difficult to get sufficient ozone into the water or that it does not remain long with existing hardware. There may be a deliberate reason for this on the part of manufacturers--too much outgassing of ozone would be an air quality and potential health issue. I find it hard to believe that no spa manufacturer has performed an ozone study, but maybe they don't see a need when marketing is moving ozonators well enough.
Starlight
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There's plenty of documented proof O3 kills bacteria. Just none on it's effectivness in a Hot Tub.
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There's plenty of documented proof O3 kills bacteria. Just none on it's effectivness in a Hot Tub.
Right On!
We need to see some accredited studies.
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One of the other issues with ozone is that it will react with anything, not just bacteria. So, if the ozone first comes into contact with minerals, it will react with the minerals, and not bacteria.
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Yes, we all know it is being utilized in drinking water, and pools and spas. The articles focus is on drinking water. GREAT, people don't sit, sweat, fart or other such bodily functions in drinking water tanks where the ozonation is done. By admission of the article, in meat processing plants, the ozone must be turned off for regular inspections. Why, probably because if inhaled at high concentrations it would kill the inspector. Ozone in a closed environment, YEAH it works. Ozone in an open environment, (pool or spa) ZERO PROOF of it's afectivness.