What I Have Read But Don't Totally Understand

[rfutscher]

I started using a hot tub about six months ago and was very confused. I searched the WEB for answers and this is a summary of what I found. I don't know what is true and what is marketing.

• There are two main processes used to treat the water. Oxidation is the breaking down of the oils and organics in your water and clumping them together so that they can be filtered out of the water. Sanitizing the water is the process of killing the bacteria and virus.

• Higher temperatures, smaller water volume, and a higher bather load increase the risk of contaminants in hot tubs compared to pools.

• There are several ways of breaking down of the oils and organics. The first is using an ozone generator. The second is to use a non-chlorine shock (potassium peroxymonosulfate or peroxymonopersulfate). A third way is to use enzymes. Hydrogen peroxide is also sometimes used.

• There are two sanitizing methods. One uses chlorine and the other uses Bromine.

• Chlorine can be added directly or produced from salt. Chlorine doesn’t work well at the high temperatures encountered in a typical spa.
I use bromine in my spa and the rest of the discussion relates to bromine.

• Bromine doesn’t work well when exposed to sunlight and is typically not used in pools. Bromine comes in two forms. It comes as bromine, the more active form and bromide, the less active form. As bromine sanitizes it is converted into bromide. If you have bromide in your water you are said to have a bromine reserve. You can change bromide back into the more active form by using ozone, a non chlorine shock product, bromine tablets which contain chlorine or bleach. The dimethylhydantoin in the bromine tablets seems to have a similar (but not identical) function in a bromine system as CYA does in a chlorine system. It tends to stabilize it but, like CYA, too much is not good. Not that much info is readily available on the effects of dimethylhydantion other than that it makes the bromine more difficult to destroy. If you test for stabilizer you will see it build up over time in a bromine spa.

• Some organisms are becoming tolerant of chlorine and bromine. I found this listing of how long some organisms can live.
o “Giardia can take up to 45 minutes to become deactivated in chlorine”
o “Noro virus takes about 30-60 minutes to deactivate”
o “Crypto is highly resistant to chlorine and can linger in a pool for up to 10 days”

• Usually a secondary sanitation method is used because of this tolerance. Typically Ionization-Oxidation, ozone, UV light and/or Hydroxyl radicals are used as the secondary systems. I do not use Ionization-Oxidation and have no information about that process.

• The UV lamp makes 99.99% of the micro orgasms inert and no longer dangerous and unable to reproduce. The micro organisms need to be exposed to the UV light for a period of time for this to happen. If the flow rate is too high the time is too short and the UV light is ineffective. If the flow rate is too slow, it can strip away a halogen residual. The UV lamp does nothing to help in the breaking down of the oils and organics. The UV lamp is typically installed in a ¾ inch pipe leading to one jet. Only 5-10% of the water from the pump passes the UV lamp. It takes 4-8 hours for all the water in the spa to pass the UV lamp. Only the water passing the UV lamp is sanitized and it does nothing to sanitize the plumbing or the hot tub itself. There are two different types of UV lamps. A low pressure lamp outputs 254 nm wavelength UV light used for germicidal action. A medium pressure lamp outputs 200-600 nm wavelength UV light that also controls all three chloramines types that are unwanted byproducts of the sanitation process.

• Ozone mostly works by contact to oxidize contaminates in the water and to kill bacteria and viruses. If the quantity of organic material is high the disinfecting abilities of the ozone will be reduced from the often listed 99.9%. Because it works by contact, the flow rate of the water is critical. If the flow rate is too high the concentration of ozone is too low to contact all of the contaminates. At low flow rates the vacuum is insufficient for the venture to fully mix the ozone with the water.
The ozone output of a typical spa generator is too low to fully oxidize contaminants and is not a total solution. One site stated 50% of the contaminates are oxidized if the ozone generator is run for 24 hours.
The ozone injector is typically installed in a ¾ inch pipe leading to one jet. Only 5-10% of the water from the pump passes the ozone filter. It takes 4-8 hours for all the water in the spa to pass the ozone filter. The ozone should be in contact with micro organisms for two minutes. In a typical spa the contact time is just a few seconds before the water goes back into the spa and the Ozone concentration is reduced. Some spas use a holding tank where the ozone remains in contact with the contaminants for a longer time. A small quantity of ozone will remain in the water for 15-25 minutes.
Only the water passing the ozone injector is sanitized and it does very little to sanitize the plumbing or the hot tub itself.
Ozone is not recommended for use indoors because of the buildup of ozone in the air. Some spas use a ozone recovery system to remove the ozone before the water is returned to the spa. This allows indoor use and a much higher concentration of ozone.
Ozone can cause bromates to form in your water. Bromates are a suspected carcinogen in drinking water.

• If an ozone generator is placed before a UV filter the UV light will turn ozone into Hydroxyl radicals. Hydroxyl radicals are the very best sanitizers but last for less than a second. Because they are so strong and fast acting there is no need for a holding tank. The name given to this is advanced oxidation process (AOP). AOP processes are so powerful they can fully oxidize all forms of organic contaminants, including microorganisms, human waste, dangerous chemicals like pharmaceutical waste and petrochemicals, fungus, algae, pesticides and other toxic elements. They also oxidize non-organic materials such as dissolved metals (iron, manganese, etc.) found in potable water, enabling their removal by filtration.

• Because the flow rate is critical ozone generators and UV lamps are usually turned off when the pump is run at a faster speed. Newer spas have a separate slower pump just for the ozone generators and UV lamps and it runs 24 hours a day.

• Shocking is the process of raising the sanitation chemicals so that they are 2 or 3 times higher than normal. This is done by converting bromide from your reserve into bromine. It is recommended that you do this once a week to make sure that the tub and plumbing are disinfected and the resistant organisms are killed. Usually a non chlorine shock is used. It usually also contains chemicals to help in breaking down the oils and organics in your water and to help clump them together so that they can be filtered out of the water. Bleach can be used to shock but it does not have any of the other chemicals. If you use ozone and bromine tablets all the bromide may already be converted into bromine and shocking won’t work. Instead you need to add fast acting bromine power to raise the level. Bromide is changed back into bromine by chlorine. If there is a large reserve of bromide the conversion from Bromide to bromine should use up the total chlorine and the total chlorine reading should be low. If your test strip shows that total chlorine is present there may not be any bromide present. If you shock it may take a day or two for the levels to return to normal and the tub can be used.

• If you don’t use ozone to help in the breaking down of the oils and organics in your water you may need to use enzymes to help with the breakdown. The level of sanitation needs to be fairly low for enzymes to work.

• If you turn on the air injectors and a lot of bubbles foam you have a foam problem. If you turn the air injection off and the bubbles dissipate fairly quickly most likely the bubbles are caused by non oxidized oils and organics. Shocking and adding a clumping agent may help. Also the use of Enzyme Products and avoiding "soft" water conditions may help. If the bubbles are larger and linger they may be caused by soaps and detergents. A defoaming agent may help.

• Some power companies offer time of day billing. If that plan is available make sure you purchase a spa that has a clock and you can program run times during off peak billing.

• Reference for ozone, UV light and AOP:
http://www.1paramount.com/products/uv_ozone/

The Spa care procedure that I am trying:
• After filling the spa I use a Bromide start packet to establish a reserve. It is available from Wal-Mart.

• I then shock with three non chlorine shock tablets to convert the bromide into bromine. They are available from Wal-Mart.

• I check the water and adjust as needed. I also add two slow release bromine tablets every week to replenish bromine that is lost. I also clean the filter every week.

• I check after every use. If the test strip shows the bromine levels are low, I add a teaspoon or two of fast acting bromine powder to bring the levels back to normal. Occasionally I will have to adjust the PH.

• I have an ozone generator, a UV lamp and I am using bromine tablets. Because they turn bromide into bromine all the bromide reserve is constantly being turned into bromine and there usually isn’t a bromine reserve. Once a week I check the spa in preparation for shocking. If there is a total chlorine reading I shock using the fast acting bromine powder. If there isn’t any total chlorine reading I shock using a non chlorine shock.

[Dr. Spa]

WOW, I'll respond inline in RED

I started using a hot tub about six months ago and was very confused. I searched the WEB for answers and this is a summary of what I found. I don't know what is true and what is marketing.

• There are two main processes used to treat the water. Oxidation is the breaking down of the oils and organics in your water and clumping them together so that they can be filtered out of the water. Sanitizing the water is the process of killing the bacteria and virus.

Oxidation does nothing to clump together anything.

• Higher temperatures, smaller water volume, and a higher bather load increase the risk of contaminants in hot tubs compared to pools.

• There are several ways of breaking down of the oils and organics. The first is using an ozone generator. The second is to use a non-chlorine shock (potassium peroxymonosulfate or peroxymonopersulfate). A third way is to use enzymes. Hydrogen peroxide is also sometimes used.

H2O2 is sometimes used as a sanitizer.

• There are two sanitizing methods. One uses chlorine and the other uses Bromine.

2 "general" ways. But there's 2 ways with bromine and 2 or more ways with chlorine. There's also a trird way using Nature2 and non-chlorine shock

• Chlorine can be added directly or produced from salt. Chlorine doesn’t work well at the high temperatures encountered in a typical spa.

Chlorine works quite well in spas!

I use bromine in my spa and the rest of the discussion relates to bromine.

• Bromine doesn’t work well when exposed to sunlight and is typically not used in pools. Bromine comes in two forms. It comes as bromine, the more active form and bromide, the less active form.

Bromine ONLY comes to you as bromide! It then has to be oxidized to become bromine. It can come as a dry granluar product or as a liquid (it's also a part of bromine tablets).

As bromine sanitizes it is converted into bromide. If you have bromide in your water you are said to have a bromine reserve. You can change bromide back into the more active form by using ozone, a non chlorine shock product, bromine tablets which contain chlorine or bleach. The dimethylhydantoin in the bromine tablets seems to have a similar (but not identical) function in a bromine system as CYA does in a chlorine system. It tends to stabilize it but, like CYA, too much is not good. Not that much info is readily available on the effects of dimethylhydantion other than that it makes the bromine more difficult to destroy. If you test for stabilizer you will see it build up over time in a bromine spa.

• Some organisms are becoming tolerant of chlorine and bromine. I found this listing of how long some organisms can live.
o “Giardia can take up to 45 minutes to become deactivated in chlorine”
o “Noro virus takes about 30-60 minutes to deactivate”
o “Crypto is highly resistant to chlorine and can linger in a pool for up to 10 days”

• Usually a secondary sanitation method is used because of this tolerance. Typically Ionization-Oxidation, ozone, UV light and/or Hydroxyl radicals are used as the secondary systems. I do not use Ionization-Oxidation and have no information about that process.

Most people do NOT use a "secondary system". These organisms tend to be extremely rare in a residential spa.

• The UV lamp makes 99.99% of the micro orgasms inert and no longer dangerous and unable to reproduce. The micro organisms need to be exposed to the UV light for a period of time for this to happen. If the flow rate is too high the time is too short and the UV light is ineffective. If the flow rate is too slow, it can strip away a halogen residual. The UV lamp does nothing to help in the breaking down of the oils and organics. The UV lamp is typically installed in a ¾ inch pipe leading to one jet. Only 5-10% of the water from the pump passes the UV lamp. It takes 4-8 hours for all the water in the spa to pass the UV lamp. Only the water passing the UV lamp is sanitized and it does nothing to sanitize the plumbing or the hot tub itself. There are two different types of UV lamps. A low pressure lamp outputs 254 nm wavelength UV light used for germicidal action. A medium pressure lamp outputs 200-600 nm wavelength UV light that also controls all three chloramines types that are unwanted byproducts of the sanitation process.

the key here is that ONLY the water passing by the lamp is sanitized...then it's returned to a "polluted" spa. The bacteria in the spa can EASILY reproduce quicker than the UV is killing it.

• Ozone mostly works by contact to oxidize contaminates in the water and to kill bacteria and viruses. If the quantity of organic material is high the disinfecting abilities of the ozone will be reduced from the often listed 99.9%. Because it works by contact, the flow rate of the water is critical.

I have no idea how to respond to this other than,basically false, flow rate is not an issue with current ozone systems.

If the flow rate is too high the concentration of ozone is too low to contact all of the contaminates. At low flow rates the vacuum is insufficient for the venture to fully mix the ozone with the water.
The ozone output of a typical spa generator is too low to fully oxidize contaminants and is not a total solution. One site stated 50% of the contaminates are oxidized if the ozone generator is run for 24 hours.
The ozone injector is typically installed in a ¾ inch pipe leading to one jet. Only 5-10% of the water from the pump passes the ozone filter. It takes 4-8 hours for all the water in the spa to pass the ozone filter. The ozone should be in contact with micro organisms for two minutes. In a typical spa the contact time is just a few seconds before the water goes back into the spa and the Ozone concentration is reduced. Some spas use a holding tank where the ozone remains in contact with the contaminants for a longer time. A small quantity of ozone will remain in the water for 15-25 minutes.
Only the water passing the ozone injector is sanitized and it does very little to sanitize the plumbing or the hot tub itself.
Ozone is not recommended for use indoors because of the buildup of ozone in the air. NO NO NO, ozone is a known pollutant and can cause serious resietory problems. It also will dissolve the type of plastic used to insulate electrical wiring. Some spas use a ozone recovery system to remove the ozone before the water is returned to the spa. This allows indoor use and a much higher concentration of ozone.
Ozone can cause bromates to form in your water. Bromates are a suspected carcinogen in drinking water.

• If an ozone generator is placed before a UV filter the UV light will turn ozone into Hydroxyl radicals. Hydroxyl radicals are the very best sanitizers but last for less than a second. Because they are so strong and fast acting there is no need for a holding tank. The name given to this is advanced oxidation process (AOP). AOP processes are so powerful they can fully oxidize all forms of organic contaminants, including microorganisms, human waste, dangerous chemicals like pharmaceutical waste and petrochemicals, fungus, algae, pesticides and other toxic elements. They also oxidize non-organic materials such as dissolved metals (iron, manganese, etc.) found in potable water, enabling their removal by filtration.

• Because the flow rate is critical ozone generators and UV lamps are usually turned off when the pump is run at a faster speed. No, ozone is turned off because it a known pollutant and causes respetory problems Newer spas have a separate slower pump just for the ozone generators and UV lamps and it runs 24 hours a day.

• Shocking is the process of raising the sanitation chemicals so that they are 2 or 3 times higher than normal. higher than that...Chem Geek knows this one. This is done by converting bromide from your reserve into bromine. It is recommended that you do this once a week to make sure that the tub and plumbing are disinfected and the resistant organisms are killed. Usually a non chlorine shock is used. It usually also contains chemicals to help in breaking down the oils and organics in your water and to help clump them together so that they can be filtered out of the water. Absolutely not. The only chemical it might contain are ph balancers. Bleach can be used to shock but it does not have any of the other chemicals SEE LAST RED COMMENTS . If you use ozone and bromine tablets all the bromide may already be converted into bromine and shocking won’t work. NOT. Or at least SOOOoooo unlikely. Instead you need to add fast acting bromine power to raise the level. Bromide is changed back into bromine by chlorine. If there is a large reserve of bromide the conversion from Bromide to bromine should use up the total chlorine and the total chlorine reading should be low. If your test strip shows that total chlorine is present there may not be any bromide present. If you shock it may take a day or two for the levels to return to normal and the tub can be used.

NO. Big misconception here. Test strips DO not measure independently for chlorine or bromine. They test for the oxidation potential of the water, and are calibrated to give the proper reading for either bromine r chlorine. Bromine test strips WILL give a positive reading if all you have in the water is chloring, and visa versa.

• If you don’t use ozone to help in the breaking down of the oils and organics in your water you may need to use enzymes to help with the breakdown. The level of sanitation needs to be fairly low for enzymes to work.

• If you turn on the air injectors and a lot of bubbles foam you have a foam problem. If you turn the air injection off and the bubbles dissipate fairly quickly most likely the bubbles are caused by non oxidized oils and organics.

ummmm, most likely the cause is a high total dissolved solids levels (think minerals).

Shocking and adding a clumping agent may help. Also the use of Enzyme Products and avoiding "soft" water conditions may help. If the bubbles are larger and linger they may be caused by soaps and detergents. A defoaming agent may help.

• Some power companies offer time of day billing. If that plan is available make sure you purchase a spa that has a clock and you can program run times during off peak billing.

• Reference for ozone, UV light and AOP:
http://www.1paramount.com/products/uv_ozone/

The Spa care procedure that I am trying:
• After filling the spa I use a Bromide start packet to establish a reserve. It is available from Wal-Mart.

• I then shock with three non chlorine shock tablets to convert the bromide into bromine. They are available from Wal-Mart.

• I check the water and adjust as needed. I also add two slow release bromine tablets every week to replenish bromine that is lost. I also clean the filter every week.

• I check after every use. If the test strip shows the bromine levels are low, I add a teaspoon or two of fast acting bromine powder to bring the levels back to normal. Occasionally I will have to adjust the PH.

• I have an ozone generator, a UV lamp and I am using bromine tablets. Because they turn bromide into bromine all the bromide reserve is constantly being turned into bromine and there usually isn’t a bromine reserve. Once a week I check the spa in preparation for shocking. If there is a total chlorine reading I shock using the fast acting bromine powder. If there isn’t any total chlorine reading I shock using a non chlorine shock.

I'm sure there's more than others will add.

[Yellow]

• If you turn on the air injectors and a lot of bubbles foam you have a foam problem. If you turn the air injection off and the bubbles dissipate fairly quickly most likely the bubbles are caused by non oxidized oils and organics.

ummmm, most likely the cause is a high total dissolved solids levels (think minerals).

Could this also be caused by Borate?

[chem geek]

I'll add my two cents in green.

WOW, I'll respond inline in RED

I started using a hot tub about six months ago and was very confused. I searched the WEB for answers and this is a summary of what I found. I don't know what is true and what is marketing.

• There are two main processes used to treat the water. Oxidation is the breaking down of the oils and organics in your water and clumping them together so that they can be filtered out of the water. Sanitizing the water is the process of killing the bacteria and virus.

Oxidation does nothing to clump together anything.

Actually some types of oxidation can lead to what is known as microflocculation which one might consider to be "clumping" but generally speaking oxidation of some bather waste results in gases and water (such as from ammonia and more slowly from urea) while for other chemicals it results in greater solubility of the chemical in water.

• Higher temperatures, smaller water volume, and a higher bather load increase the risk of contaminants in hot tubs compared to pools.

True.

• There are several ways of breaking down of the oils and organics. The first is using an ozone generator. The second is to use a non-chlorine shock (potassium peroxymonosulfate or peroxymonopersulfate). A third way is to use enzymes. Hydrogen peroxide is also sometimes used.

H2O2 is sometimes used as a sanitizer.

It should be noted that chlorine is both a disinfectant (what you call a sanitizer) AND an oxidizer. Bromine is as well but is a weaker oxidizer so needs more help (i.e. supplementation). Hydrogen peroxide is both, but weaker than chlorine. In the Baquacil/biguanide/PHMB system where this chemical is the disinfectant, hydrogen peroxide is used as the oxidizer. Note that hydrogen peroxide is not approved by the EPA as a disinfectant.

• There are two sanitizing methods. One uses chlorine and the other uses Bromine.

2 "general" ways. But there's 2 ways with bromine and 2 or more ways with chlorine. There's also a trird way using Nature2 and non-chlorine shock

I presume you are referring to bulk water disinfection. Ozone and UV also disinfect, but only affect pathogens floating through the circulation system so do nothing to prevent person-to-person transmission of disease nor to affect pathogens growing on surfaces (unless enough ozone is used to provide a residual, but that is risky in a spa due to outgassing of ozone which is an EPA air pollutant).

There are only four chemicals found in EPA-approved disinfectants for spas: chlorine, bromine, Baquacil/biguanide/PHMB, Nature² with MPS non-chlorine shock.

• Chlorine can be added directly or produced from salt. Chlorine doesn’t work well at the high temperatures encountered in a typical spa.

Chlorine works quite well in spas!

It is not true that chlorine does not work well at high temperatures. That is a myth. Disinfectants generally work faster to kill pathogens and oxidize at higher temperatures and such killing increases faster at higher temperatures than the reproduction rates of pathogens.

I use bromine in my spa and the rest of the discussion relates to bromine.

• Bromine doesn’t work well when exposed to sunlight and is typically not used in pools. Bromine comes in two forms. It comes as bromine, the more active form and bromide, the less active form.

Bromine ONLY comes to you as bromide! It then has to be oxidized to become bromine. It can come as a dry granluar product or as a liquid (it's also a part of bromine tablets).

When bromine is sold in active form it comes in bromine tabs of which there are two types: BCDMH which has both bromine and chlorine in it and DBDMH which has only bromine in it. When you have bromide in the water, oxidizers can convert it to bromine and that's what happens when you start with a bromide bank and use BCDMH tabs where the chlorine creates bromine from the bromide. The same is true if you don't use tabs and just add an oxidizer to water with bromide in it -- such oxidizer can be chlorine or non-chlorine shock (MPS).

As bromine sanitizes it is converted into bromide. If you have bromide in your water you are said to have a bromine reserve. You can change bromide back into the more active form by using ozone, a non chlorine shock product, bromine tablets which contain chlorine or bleach. The dimethylhydantoin in the bromine tablets seems to have a similar (but not identical) function in a bromine system as CYA does in a chlorine system. It tends to stabilize it but, like CYA, too much is not good. Not that much info is readily available on the effects of dimethylhydantion other than that it makes the bromine more difficult to destroy. If you test for stabilizer you will see it build up over time in a bromine spa.

This is similar with chlorine where when chlorine is used up it converts to chloride (as in sodium chloride salt).

As for ozone oxidizing bromide to bromine, it does that but it ALSO oxidizes bromine to bromate so when using an ozonator some bromine gets spent (used up) into a dead-end form. So over time you will deplete your bromide bank if you use an ozonator and don't add more sodium bromide or add more bromine from tabs.

Yes, DMH is similar to CYA in terms of delivering bromine (vs. chlorine) in slow-dissolving tablet form, but it doesn't bind as strongly to bromine as CYA does to chlorine. Nevertheless, overuse of tabs may buildup too much DMH but we don't know the equilibrium constants for this so can't say for sure how much is too much. I'm not sure of DMH stabilizer tests for a bromine spa. Tests for "stabilizer" usually mean tests for CYA and those will not test for DMH.

• Some organisms are becoming tolerant of chlorine and bromine. I found this listing of how long some organisms can live.
o “Giardia can take up to 45 minutes to become deactivated in chlorine”
o “Noro virus takes about 30-60 minutes to deactivate”
o “Crypto is highly resistant to chlorine and can linger in a pool for up to 10 days”

It is not true that the organisms you list are becoming more tolerant of chlorine and bromine. Giardia and Crypto are protozoan oocysts that have ALWAYS been more resistant to chlorine and bromine and most environmental stresses and chemicals. That's why they are oocysts. Evolutionary pressure selected these thick coated shells to protect these organisms in a harsh environment long before chlorine or bromine were ever present and probably long before humans walked the planet. As for the Noro virus, most viruses take longer than simple coliform bacteria to kill, but again the variance for this among viruses is not due to chlorine or bromine but due to selective pressures to survive in the environment generally. You should not mix up the evolution of pathogens becoming resistant to antibiotics with the use of chlorine or bromine. The mechanisms from chlorine in killing pathogens are much broader than that from antibiotics so single mutations are generally unlikely to provide sufficient incremental resistance. Also, chlorine and bromine tend to be used in amounts that provide nearly complete kill unless the bacteria form biofilms.

Pathogens and indeed many cells do have mechanisms against oxidants (i.e. they contain anti-oxidants) though that did not develop specifically because of chlorine. Also, some cells in the human body actually produce hypochlorous acid (e.g. white blood cells such as neutrophils). So as a result, some pathogens have developed more anti-oxidants to help neutralize this hypochlorous acid, but these processes occurred long before chlorine and bromine were in use by man and indeed likely before humans existed.

• Usually a secondary sanitation method is used because of this tolerance. Typically Ionization-Oxidation, ozone, UV light and/or Hydroxyl radicals are used as the secondary systems. I do not use Ionization-Oxidation and have no information about that process.

Most people do NOT use a "secondary system". These organisms tend to be extremely rare in a residential spa.

For commercial/public pools, the use of ozone or UV for supplemental disinfection is sometimes used and the new Model Aquatic Health Code in development by the CDC will require their use in high-risk venues. However, these systems are not usually used in residential situations since the risks are much lower. The more resistant pathogens are not generally found blowing in the environment or commonly found in most people so you'll only find Crypto (the only one that's resistant enough to care about) from people who have it. Even if you look at the stats for commercial/public pools, the outbreak rate is very low at around 0.03% per year. The problem is that one infected person can infect dozens or even hundreds of others in such pools. So unless you are sharing your hot tub with an infected person (i.e. someone who has diarrhea but insists on using your spa anyway), your risk is extremely low.

Ozone systems ARE commonly used in residential spas, but not so much for disinfection as for supplemental oxidation of bather waste. This is best in heavily used spas (i.e. every day or two) since that results in lower chlorine consumption. However, in infrequently used spas, ozone depletes chlorine since it converts it to chloride and chlorate. As noted earlier, with bromine spas ozone can create more bromine from bromide so can help maintain a background level of bromine.

• The UV lamp makes 99.99% of the micro orgasms inert and no longer dangerous and unable to reproduce. The micro organisms need to be exposed to the UV light for a period of time for this to happen. If the flow rate is too high the time is too short and the UV light is ineffective. If the flow rate is too slow, it can strip away a halogen residual. The UV lamp does nothing to help in the breaking down of the oils and organics. The UV lamp is typically installed in a ¾ inch pipe leading to one jet. Only 5-10% of the water from the pump passes the UV lamp. It takes 4-8 hours for all the water in the spa to pass the UV lamp. Only the water passing the UV lamp is sanitized and it does nothing to sanitize the plumbing or the hot tub itself. There are two different types of UV lamps. A low pressure lamp outputs 254 nm wavelength UV light used for germicidal action. A medium pressure lamp outputs 200-600 nm wavelength UV light that also controls all three chloramines types that are unwanted byproducts of the sanitation process.

the key here is that ONLY the water passing by the lamp is sanitized...then it's returned to a "polluted" spa. The bacteria in the spa can EASILY reproduce quicker than the UV is killing it.

• Ozone mostly works by contact to oxidize contaminates in the water and to kill bacteria and viruses. If the quantity of organic material is high the disinfecting abilities of the ozone will be reduced from the often listed 99.9%. Because it works by contact, the flow rate of the water is critical.

I have no idea how to respond to this other than,basically false, flow rate is not an issue with current ozone systems.

If the flow rate is too high the concentration of ozone is too low to contact all of the contaminates. At low flow rates the vacuum is insufficient for the venture to fully mix the ozone with the water.
The ozone output of a typical spa generator is too low to fully oxidize contaminants and is not a total solution. One site stated 50% of the contaminates are oxidized if the ozone generator is run for 24 hours.
The ozone injector is typically installed in a ¾ inch pipe leading to one jet. Only 5-10% of the water from the pump passes the ozone filter. It takes 4-8 hours for all the water in the spa to pass the ozone filter. The ozone should be in contact with micro organisms for two minutes. In a typical spa the contact time is just a few seconds before the water goes back into the spa and the Ozone concentration is reduced. Some spas use a holding tank where the ozone remains in contact with the contaminants for a longer time. A small quantity of ozone will remain in the water for 15-25 minutes.
Only the water passing the ozone injector is sanitized and it does very little to sanitize the plumbing or the hot tub itself.
Ozone is not recommended for use indoors because of the buildup of ozone in the air. NO NO NO, ozone is a known pollutant and can cause serious resietory problems. It also will dissolve the type of plastic used to insulate electrical wiring. Some spas use a ozone recovery system to remove the ozone before the water is returned to the spa. This allows indoor use and a much higher concentration of ozone.
Ozone can cause bromates to form in your water. Bromates are a suspected carcinogen in drinking water.

To prevent problems with ozone outgassing and damage to equipment, most residential ozone systems for spas are designed to be weak enough to not be a problem. If they are strong as in commercial/pubic systems, then they have degassing systems. In some residential spas turning on the jets turns off the ozonator to help prevent outgassing.

• If an ozone generator is placed before a UV filter the UV light will turn ozone into Hydroxyl radicals. Hydroxyl radicals are the very best sanitizers but last for less than a second. Because they are so strong and fast acting there is no need for a holding tank. The name given to this is advanced oxidation process (AOP). AOP processes are so powerful they can fully oxidize all forms of organic contaminants, including microorganisms, human waste, dangerous chemicals like pharmaceutical waste and petrochemicals, fungus, algae, pesticides and other toxic elements. They also oxidize non-organic materials such as dissolved metals (iron, manganese, etc.) found in potable water, enabling their removal by filtration.

UV after ozone is one way to produce hydroxyl radicals but that is very uncommon in residential spas. One can also produce them via boron-doped diamond electrodes as is done in the ACE saltwater sanitizing system though that also produces chlorine in addition to hydroxyl radicals. There are also newer systems that produce more hydroxyl radicals such as those from Clear Comfort. Hydroxyl radicals are indeed powerful oxidizers and are very short-lived, but generally such systems are more expensive.

• Because the flow rate is critical ozone generators and UV lamps are usually turned off when the pump is run at a faster speed. No, ozone is turned off because it a known pollutant and causes respetory problems Newer spas have a separate slower pump just for the ozone generators and UV lamps and it runs 24 hours a day.

• Shocking is the process of raising the sanitation chemicals so that they are 2 or 3 times higher than normal. higher than that...Chem Geek knows this one. This is done by converting bromide from your reserve into bromine. It is recommended that you do this once a week to make sure that the tub and plumbing are disinfected and the resistant organisms are killed. Usually a non chlorine shock is used. It usually also contains chemicals to help in breaking down the oils and organics in your water and to help clump them together so that they can be filtered out of the water. Absolutely not. The only chemical it might contain are ph balancers. Bleach can be used to shock but it does not have any of the other chemicals SEE LAST RED COMMENTS . If you use ozone and bromine tablets all the bromide may already be converted into bromine and shocking won’t work. NOT. Or at least SOOOoooo unlikely. Instead you need to add fast acting bromine power to raise the level. Bromide is changed back into bromine by chlorine. If there is a large reserve of bromide the conversion from Bromide to bromine should use up the total chlorine and the total chlorine reading should be low. If your test strip shows that total chlorine is present there may not be any bromide present. If you shock it may take a day or two for the levels to return to normal and the tub can be used.

NO. Big misconception here. Test strips DO not measure independently for chlorine or bromine. They test for the oxidation potential of the water, and are calibrated to give the proper reading for either bromine r chlorine. Bromine test strips WILL give a positive reading if all you have in the water is chloring, and visa versa.

First of all, in a properly maintained pool or spa, shocking is not normally necessary. If you add enough oxidizer after a soak, you normally would not need to shock. That's mostly the case for chlorine pools and spas. For bromine, as I noted earlier it's not as good an oxidizer so may need some help. If you don't have an ozonator, then you may need to add chlorine once a week or so to help oxidize chemicals that bromine has trouble oxidizing. As for how high to shock, it depends on what needs to be oxidized and how quickly you want it done.

• If you don’t use ozone to help in the breaking down of the oils and organics in your water you may need to use enzymes to help with the breakdown. The level of sanitation needs to be fairly low for enzymes to work.

Enzymes are another way to help oxidize bather waste. They don't oxidize them by themselves -- they are catalysts that speed up the reaction rate from another oxidizer be it chlorine, bromine, or even oxygen in the water.

• If you turn on the air injectors and a lot of bubbles foam you have a foam problem. If you turn the air injection off and the bubbles dissipate fairly quickly most likely the bubbles are caused by non oxidized oils and organics.

ummmm, most likely the cause is a high total dissolved solids levels (think minerals).

Foaming is usually caused by soap-like chemicals. Increasing hardness (calcium or magnesium) reduces foaming. Having cleaner swimsuits without leftover detergent helps reduce foaming.

Shocking and adding a clumping agent may help. Also the use of Enzyme Products and avoiding "soft" water conditions may help. If the bubbles are larger and linger they may be caused by soaps and detergents. A defoaming agent may help.

Defoamers can work if not overused, but scooping out foam that generally is on the surface of the water helps. Avoiding the problem in the first place is best. Using a scum ball can also collect surface oils as well as soap that can lead to foaming.

• Some power companies offer time of day billing. If that plan is available make sure you purchase a spa that has a clock and you can program run times during off peak billing.

• Reference for ozone, UV light and AOP:
http://www.1paramount.com/products/uv_ozone/

There is so much mixed info there that I'm not going to comment on it.

The Spa care procedure that I am trying:
• After filling the spa I use a Bromide start packet to establish a reserve. It is available from Wal-Mart.

• I then shock with three non chlorine shock tablets to convert the bromide into bromine. They are available from Wal-Mart.

You could just use chlorine bleach to activate the bromide to bromine less expensively. However, if the spa water is older and you don't want to create chlorinated disinfection by-products, then non-chlorine shock (MPS) is fine to use.

• I check the water and adjust as needed. I also add two slow release bromine tablets every week to replenish bromine that is lost. I also clean the filter every week.

• I check after every use. If the test strip shows the bromine levels are low, I add a teaspoon or two of fast acting bromine powder to bring the levels back to normal. Occasionally I will have to adjust the PH.

• I have an ozone generator, a UV lamp and I am using bromine tablets. Because they turn bromide into bromine all the bromide reserve is constantly being turned into bromine and there usually isn’t a bromine reserve. Once a week I check the spa in preparation for shocking. If there is a total chlorine reading I shock using the fast acting bromine powder. If there isn’t any total chlorine reading I shock using a non chlorine shock.

If you properly added 1/2 ounce of sodium bromide per 100 gallons, then that's roughly 30 ppm bromide which should NOT all get converted to bromine. As I noted before, over time the ozone will deplete the bromide by converting some of it to bromate. Unfortunately, there is no easy way to test for bromide separately from chloride similar to how there is no easy way to test for bromine separately from chlorine.

I'm sure there's more than others will add.

[rfutscher]

Thank you chem geek for explaining the chemistry.