Spa Itch

[Hillbilly Hot Tub]

I am new to this forum, but not to hot tubs. We specialize in service and water chemistry. I have seen a few things mentioned about a rash/ irritation from people that are using a hot tub. I wanted to try to clear up a couple of things. First, VERY few people are allergic to the chemicals such as chlorine and bromine. The itch is usually caused by the PH in the tub being off or to high amount of sanitizer UNLESS it is an ongoing itch, wont go away. If your doctor says you have spa dermatitis this is what it is....(CDC Fact Sheet) Pseudomonas Dermatitis/Folliculitis a RWI(recreational water illness) Dermititis is an infection of the skin. The skin may become itchy and progress into a bumby rash that may become tender. There may also be pussed filled blisters usually surrounding the hair follicles. It is caused by the germ Pseudomonas aeruginosa. This germ is common in the environment (water,soil) and is microscopic. It is spread by direct contact with infected water. The rash usually occurs within a few days of swimming in poorly maintained hot tubs or pools, but can also be spread by swimming in a contaminated pool or lake. Be aware that hot tubs and spas have warmer water thn pools, so chlorine and other disinfectants evaporate faster. This leaves hot tubs and spas at risk fpr the spread of RWI's. Ensure frequent testing, control of bromine/chlorie levels and PH control are likley to prevent the spread of dermatitis. You can find more info at www.healthyswimming.org

[TinyBubbles]

Perhaps some people should use the word sensitivity instead of allergy. I'm fortunate to have both an allergist and dermatologist in the family. They say the most common reaction people have is to bromine. The least common reaction is to chlorine, since most people are exposed to this every day from their municipal water supply. Substances can be an irritant without being an allergen. Dry skin tends to be the culprit in many instances. Soaking in hot water in the winter, that's understandable. Once you get out of the hot water, you only have a few minutes to get a barrier on your skin before it dries out. Not to mention the fact that hot water opens our pores and allows any chemicals, acidic water or germs to get deep inside. Some people get itchy spots where jets hit them. My favorite seat has a great big jet right in the middle of my lower back and I get dry and bumpy there and have to use extra moisturizer. I've always had problems with eczema, hives and contact dermatitis, so I was very worried about having a spa. I have to avoid bromine and MPS. Now that it's very cold and the air is very dry, my eczema has flared up, which is mostly my fault for not always moisturizing when getting out of the tub.

[ncspa]

Perhaps some people should use the word sensitivity instead of allergy. I'm fortunate to have both an allergist and dermatologist in the family. They say the most common reaction people have is to bromine. The least common reaction is to chlorine, since most people are exposed to this every day from their municipal water supply. Substances can be an irritant without being an allergen. Dry skin tends to be the culprit in many instances. Soaking in hot water in the winter, that's understandable. Once you get out of the hot water, you only have a few minutes to get a barrier on your skin before it dries out. Not to mention the fact that hot water opens our pores and allows any chemicals, acidic water or germs to get deep inside. Some people get itchy spots where jets hit them. My favorite seat has a great big jet right in the middle of my lower back and I get dry and bumpy there and have to use extra moisturizer. I've always had problems with eczema, hives and contact dermatitis, so I was very worried about having a spa. I have to avoid bromine and MPS. Now that it's very cold and the air is very dry, my eczema has flared up, which is mostly my fault for not always moisturizing when getting out of the tub.

Interesting - I have really dry skin myself and have been concerned that spa use might exacerbate the problem - not eczema, just dry skin. Is this something that can be controlled by simply using moisturizers after tubbing? Or should I be more concerned? Thanks....helpful thread

[pondlife]

Interesting - I have really dry skin myself and have been concerned that spa use might exacerbate the problem - not eczema, just dry skin. Is this something that can be controlled by simply using moisturizers after tubbing? Or should I be more concerned? Thanks....helpful thread

It is an uphill battle to apply emollient to potentially dry skin to prevent dermatitis developing. I find twice daily application of a light oil (e.g. Oilatum emollient) emollient mixed with some water applied after showering off after a spa soak just controls my skin. I also have to wear shorts in the house to keep my legs cool. Here in the UK low humidity is not a problem. Currently 100% and 11 degrees celcius outside at present.

Thanks for the tip about MPS. I will try chlorine shocks and see if any improvement on my legs.

Pondlife

[TinyBubbles]

Perhaps some people should use the word sensitivity instead of allergy. I'm fortunate to have both an allergist and dermatologist in the family. They say the most common reaction people have is to bromine. The least common reaction is to chlorine, since most people are exposed to this every day from their municipal water supply. Substances can be an irritant without being an allergen. Dry skin tends to be the culprit in many instances. Soaking in hot water in the winter, that's understandable. Once you get out of the hot water, you only have a few minutes to get a barrier on your skin before it dries out. Not to mention the fact that hot water opens our pores and allows any chemicals, acidic water or germs to get deep inside. Some people get itchy spots where jets hit them. My favorite seat has a great big jet right in the middle of my lower back and I get dry and bumpy there and have to use extra moisturizer. I've always had problems with eczema, hives and contact dermatitis, so I was very worried about having a spa. I have to avoid bromine and MPS. Now that it's very cold and the air is very dry, my eczema has flared up, which is mostly my fault for not always moisturizing when getting out of the tub.

Interesting - I have really dry skin myself and have been concerned that spa use might exacerbate the problem - not eczema, just dry skin. Is this something that can be controlled by simply using moisturizers after tubbing? Or should I be more concerned? Thanks....helpful thread

I think you should be fine if you apply a good moisturizer. I have a heat pump, so the air in my house is really dry too. It's a constant battle keeping those humidifiers filled. Another tip is to cover any problems areas with clothing after a soak. My husband tends to get cracked feet in the cold, dry weather. If he puts on socks or slippers after soaking, he's fine. My problem area is the space between my fingers. Which make sense, since hands are constantly exposed. Now I put a dab of petroleum jelly in between each one after soaking. It sounds crazy, but dr.'s recommend using crisco. Just be careful if you put it on your feet, it's slick when you get in the shower.

[DickP3]

Perhaps some people should use the word sensitivity instead of allergy. I'm fortunate to have both an allergist and dermatologist in the family. They say the most common reaction people have is to bromine. The least common reaction is to chlorine, since most people are exposed to this every day from their municipal water supply. Substances can be an irritant without being an allergen. Dry skin tends to be the culprit in many instances. Soaking in hot water in the winter, that's understandable. Once you get out of the hot water, you only have a few minutes to get a barrier on your skin before it dries out. Not to mention the fact that hot water opens our pores and allows any chemicals, acidic water or germs to get deep inside. Some people get itchy spots where jets hit them. My favorite seat has a great big jet right in the middle of my lower back and I get dry and bumpy there and have to use extra moisturizer. I've always had problems with eczema, hives and contact dermatitis, so I was very worried about having a spa. I have to avoid bromine and MPS. Now that it's very cold and the air is very dry, my eczema has flared up, which is mostly my fault for not always moisturizing when getting out of the tub.

Interesting - I have really dry skin myself and have been concerned that spa use might exacerbate the problem - not eczema, just dry skin. Is this something that can be controlled by simply using moisturizers after tubbing? Or should I be more concerned? Thanks....helpful thread

I think you should be fine if you apply a good moisturizer. I have a heat pump, so the air in my house is really dry too. It's a constant battle keeping those humidifiers filled. Another tip is to cover any problems areas with clothing after a soak. My husband tends to get cracked feet in the cold, dry weather. If he puts on socks or slippers after soaking, he's fine. My problem area is the space between my fingers. Which make sense, since hands are constantly exposed. Now I put a dab of petroleum jelly in between each one after soaking. It sounds crazy, but dr.'s recommend using crisco. Just be careful if you put it on your feet, it's slick when you get in the shower.

We've experienced "spa itch" ourselves both at a resort and recently, here at home. At home, the itch didn't happen until about a month after our first startup. I wonder if the amount of combined chlorine in the water contributes to the itch. When the tub is first filled, the combined chlorine would be zero (and we had no itch). As time progressed, if there was insufficient shock or ozonation, then wouldn't the combined chlorine rise? Theoretically this shouldn't happen with our 24/7 circulation pump and ozonator. But, if the ozonator failed then the combined chlorine might rise.

We have ordered a TF100 test kit and will be testing for CC soon. Right now, it's just strips.

[poolyeti]

I wonder if the amount of combined chlorine in the water contributes to the itch. When the tub is first filled, the combined chlorine would be zero (and we had no itch). As time progressed, if there was insufficient shock or ozonation, then wouldn't the combined chlorine rise? Theoretically this shouldn't happen with our 24/7 circulation pump and ozonator. But, if the ozonator failed then the combined chlorine might rise.

DickP3, combined chlorine levels aren't something that inevitably must increase with time. The cause of elevated CC is insufficient FC. If you're shocking with adequate reguarity then your problem isn't combined chlorine. But you are right that an inactive ozonator would contribute to higher CC

[chem geek]

DickP3,

Did you use Dichlor as your source of chlorine and if so, how much did you use how often (both regular addition and any shocking, if Dichlor was used for shocking) and what is the size of your spa? [EDIT] Never mind. I see from this thread that you did use Dichlor, and that your spa probably had over 100 ppm CYA. [END-EDIT]

With every 10 ppm Free Chlorine (FC) added by Dichlor, it also adds 9 ppm to Cyanuric Acid (CYA) and this CYA does build up as it does not go away until the next drain/refill. Higher CYA levels reduce chlorine's effectiveness so could allow some heartier bacteria to grow. It also slows down all chemical reactions with chlorine since the disinfecting chlorine (hypochlorous acid) concentration is effectively much lower. That slows down the breakpoint reaction with chlorine so could lead to a buildup of Combined Chlorine, specifically monochloramine, but would probably require rather frequent usage (possibly twice a day or more than one person or a smaller-than-usual tub).

I just got a new and better breakpoint chlorination model and the results do show a slower-than-desirable breakpoint of ammonia by chlorine at the higher CYA level. Assuming you added one teaspoon of Dichlor (half a teaspoon per person as directed by your spa store) and did this twice a day, then that would be about 3 ppm FC per day. At this FC level and 100 ppm CYA, the breakpoint is only 50% complete after a little more than 4 hours and is 90% complete after 12-1/2 hours. The actual times could be shorter than this since the model is at 77F and not spa temperature (so maybe twice as fast, though earlier models showed fairly small temperature dependence on the rate constants). If you instead only used Dichlor for a week and then switched to unscented bleach to get around 4 ppm FC at 20 ppm CYA, then the breakpoint would be much faster at 50% completion in 38 minutes and 90% completion in about 2 hours.

In theory, your ozonator should have eliminated combined chlorine. If your ozonator stopped working, then it may also be that one-half teaspoon of Dichlor per person-soak isn't enough anyway, even if the CYA wasn't too high. This is what poolyeti was saying about the FC not being high enough. Without enough FC, the CC will build up. Nevertheless, I don't think the monochloramine will be that irritating to most people, but it clearly is to some as is shown in this link where it appears that some people may be sensitive to the 1 ppm CC of monochloramine put into drinking water and used for showering or bathing (it used to be that 1 ppm FC was used instead, but that can cause disinfection byproducts from exposure to organics when in the pipes and it also doesn't last as long so can lead to unprotected water in dead-end systems).

Richard

[DickP3]

DickP3,

Did you use Dichlor as your source of chlorine and if so, how much did you use how often (both regular addition and any shocking, if Dichlor was used for shocking) and what is the size of your spa?

With every 10 ppm Free Chlorine (FC) added by Dichlor, it also adds 9 ppm to Cyanuric Acid (CYA) and this CYA does build up as it does not go away until the next drain/refill. Higher CYA levels reduce chlorine's effectiveness so could allow some heartier bacteria to grow. It also slows down all chemical reactions with chlorine since the disinfecting chlorine (hypochlorous acid) concentration is effectively much lower. That slows down the breakpoint reaction with chlorine so could lead to a buildup of Combined Chlorine, specifically monochloramine, but would probably require rather frequent usage (possibly twice a day or more than one person or a smaller-than-usual tub).

Richard

Hi Richard We have a new 450 gal tub with a circulation pump and ozonator running 24/7. It was first filled about 5 weeks ago. Two people use the tub, usually twice a day. As recommended by the manufacturer, we have been using Dichlor and no shocking since the ozonator is supposed to do that. As of Jan 19, we have added 69 tsp of Dichlor so our CYA probably is close to 100 ppm. We are trying your suggestion of 9 ounces of 6% bleach added in the evening (response to "Another Newbie needing help...).

We seem to have a "smell" that isn't chlorine that started about a week ago. That smell seems to be increasing. Our itching also seems to be increasing. The only reason we bought the tub was to relieve asthritis pain and stiffness and so are reluctant to quit using it altogether. We are wondering if the ozonator isn't working and have a service call scheduled for this week.

What I'm trying to do is find out why the tub that was wonderful, relaxing and non-itching 5 weeks ago has now become a problem. What has changed since the beginning? Hence, my question about combined chlorine. I know we have high CYA levels but my understanding is that high CYA does not cause itching.

[chem geek]

(I edited my previous post while you responded to my original, so take another look at it). High CYA by itself does not cause itching, but CYA interferes with chlorine's effectiveness by binding to it. At higher CYA levels, more of the chlorine is "attached" to CYA and essentially ineffective. So the level of disinfection in the spa is less at the higher CYA level unless you use a higher FC level to compensate for that.

It is pretty easy to separate out the possibility of Combined Chlorine from other factors. Just shock the spa with unscented bleach, do not use the spa nor run any jets (just run the circulation pump) and if possible keep the spa uncovered for as long as you can. If the FC rapidly drops, then you may have excess ammonia/urea in the spa that needs to get broken down and you'll need to add more bleach to eliminate it. If you get the TF100 test kit you ordered, you'll be able to easily test separately and accurately the FC vs. CC. Since that's definitive, why don't you just wait for the kit and can then go from there -- unless you don't mind not using the spa for a few days in which case you can seriously shock it with unscented bleach (be sure to add it SLOWLY over a return flow with the circulation pump running and try and keep the cover off for as long as possible).

Given that the level of smell has recently increased and that you are using a higher level of chlorine and the smell isn't the fresh smell of chlorine, I suspect that you did have excess ammonia/urea and that now you are getting rid of it and that smells due to the monochoramine as well as small amounts of dichloramine and very small amounts of nitrogen trichloride. It sure seems to me like your ozonator wasn't working as it should have prevented such buildup. That's my best guess at this point.

Richard

[TinyBubbles]

DickP3,

Did you use Dichlor as your source of chlorine and if so, how much did you use how often (both regular addition and any shocking, if Dichlor was used for shocking) and what is the size of your spa?

With every 10 ppm Free Chlorine (FC) added by Dichlor, it also adds 9 ppm to Cyanuric Acid (CYA) and this CYA does build up as it does not go away until the next drain/refill. Higher CYA levels reduce chlorine's effectiveness so could allow some heartier bacteria to grow. It also slows down all chemical reactions with chlorine since the disinfecting chlorine (hypochlorous acid) concentration is effectively much lower. That slows down the breakpoint reaction with chlorine so could lead to a buildup of Combined Chlorine, specifically monochloramine, but would probably require rather frequent usage (possibly twice a day or more than one person or a smaller-than-usual tub).

Richard

Hi Richard We have a new 450 gal tub with a circulation pump and ozonator running 24/7. It was first filled about 5 weeks ago. Two people use the tub, usually twice a day. As recommended by the manufacturer, we have been using Dichlor and no shocking since the ozonator is supposed to do that. As of Jan 19, we have added 69 tsp of Dichlor so our CYA probably is close to 100 ppm. We are trying your suggestion of 9 ounces of 6% bleach added in the evening (response to "Another Newbie needing help...).

Ok, let's hope my math skills aren't failing me. Soaking 2 times daily for 5 weeks, would be equal to 70 soaks. You've added about 1 tsp. of dichlor per soak for 2 people in a 450 gallon tub. Sounds a little on the low side to me. Were you checking your FC about an hour after this dose to see what it was? You should have been adding enough dichlor to raise the FC level to 3-5 ppm in order to have proper sanitization. It's important to make sure that your water maintains this level for awhile, in order to be effective. One valuable lesson I learned on this forum and others, is to go by FC levels, not amounts added. Do you add the dichlor after soaking? Do you know what your FC levels are when you are soaking? Hi sanitizer levels or low ph can cause skin irritation. Do you have a rash or just itchy skin? Don't worry, you are not going to have to give up your soaks. You are new to water chemistry and it's a challenge in the beginning. You are in the right place to get it sorted out.

[Hillbilly Hot Tub]

DickP3,

Did you use Dichlor as your source of chlorine and if so, how much did you use how often (both regular addition and any shocking, if Dichlor was used for shocking) and what is the size of your spa?

With every 10 ppm Free Chlorine (FC) added by Dichlor, it also adds 9 ppm to Cyanuric Acid (CYA) and this CYA does build up as it does not go away until the next drain/refill. Higher CYA levels reduce chlorine's effectiveness so could allow some heartier bacteria to grow. It also slows down all chemical reactions with chlorine since the disinfecting chlorine (hypochlorous acid) concentration is effectively much lower. That slows down the breakpoint reaction with chlorine so could lead to a buildup of Combined Chlorine, specifically monochloramine, but would probably require rather frequent usage (possibly twice a day or more than one person or a smaller-than-usual tub).

Richard

Hi Richard We have a new 450 gal tub with a circulation pump and ozonator running 24/7. It was first filled about 5 weeks ago. Two people use the tub, usually twice a day. As recommended by the manufacturer, we have been using Dichlor and no shocking since the ozonator is supposed to do that. As of Jan 19, we have added 69 tsp of Dichlor so our CYA probably is close to 100 ppm. We are trying your suggestion of 9 ounces of 6% bleach added in the evening (response to "Another Newbie needing help...).

We seem to have a "smell" that isn't chlorine that started about a week ago. That smell seems to be increasing. Our itching also seems to be increasing. The only reason we bought the tub was to relieve asthritis pain and stiffness and so are reluctant to quit using it altogether. We are wondering if the ozonator isn't working and have a service call scheduled for this week.

What I'm trying to do is find out why the tub that was wonderful, relaxing and non-itching 5 weeks ago has now become a problem. What has changed since the beginning? Hence, my question about combined chlorine. I know we have high CYA levels but my understanding is that high CYA does not cause itching.

You did not mention if you have been adjusting your PH if not test and adjust as needed

[DickP3]

DickP3,

Did you use Dichlor as your source of chlorine and if so, how much did you use how often (both regular addition and any shocking, if Dichlor was used for shocking) and what is the size of your spa?

With every 10 ppm Free Chlorine (FC) added by Dichlor, it also adds 9 ppm to Cyanuric Acid (CYA) and this CYA does build up as it does not go away until the next drain/refill. Higher CYA levels reduce chlorine's effectiveness so could allow some heartier bacteria to grow. It also slows down all chemical reactions with chlorine since the disinfecting chlorine (hypochlorous acid) concentration is effectively much lower. That slows down the breakpoint reaction with chlorine so could lead to a buildup of Combined Chlorine, specifically monochloramine, but would probably require rather frequent usage (possibly twice a day or more than one person or a smaller-than-usual tub).

Richard

Hi Richard We have a new 450 gal tub with a circulation pump and ozonator running 24/7. It was first filled about 5 weeks ago. Two people use the tub, usually twice a day. As recommended by the manufacturer, we have been using Dichlor and no shocking since the ozonator is supposed to do that. As of Jan 19, we have added 69 tsp of Dichlor so our CYA probably is close to 100 ppm. We are trying your suggestion of 9 ounces of 6% bleach added in the evening (response to "Another Newbie needing help...).

We seem to have a "smell" that isn't chlorine that started about a week ago. That smell seems to be increasing. Our itching also seems to be increasing. The only reason we bought the tub was to relieve asthritis pain and stiffness and so are reluctant to quit using it altogether. We are wondering if the ozonator isn't working and have a service call scheduled for this week.

What I'm trying to do is find out why the tub that was wonderful, relaxing and non-itching 5 weeks ago has now become a problem. What has changed since the beginning? Hence, my question about combined chlorine. I know we have high CYA levels but my understanding is that high CYA does not cause itching.

You did not mention if you have been adjusting your PH if not test and adjust as needed

HillBilly Hot Tub - TA is about 80 ppm and pH is 7.2-7.8. These are strip numbers.

chem geek - The hot tub serviceman today determined that our ozonator WAS NOT working! So, you were right on, Richard. It will be interesting to see how long the new one works; supposed to last 5 years.

Now, I'll try to get the FC right and see if the CC is down now that the ozonator is working. TF100 kit is supposed to be delivered tomorrow.

[chem geek]

chem geek - The hot tub serviceman today determined that our ozonator WAS NOT working! So, you were right on, Richard. It will be interesting to see how long the new one works; supposed to last 5 years.

Now, I'll try to get the FC right and see if the CC is down now that the ozonator is working. TF100 kit is supposed to be delivered tomorrow.

That's great news that you've figured out the problem. So if the CYA is still high, then you might consider a drain/refill to start over. Either that or you'll have to keep a higher FC level and keep the cover off longer when you get out to give the chlorine a chance to break down all the ammonia/urea (that mostly comes from sweat). The ozonator will certainly help, but it's probably best not to take too many chances. One thing you should keep track of is whether you notice any change in chlorine usage (at your current CYA level) as that can be a guide as to whether or not the ozonator is depleting chlorine and by how much. After a drain/refill and adding Dichlor until you get to 20 ppm CYA (about a week), then see what your chlorine usage is again -- it will probably be higher since there's probably a little more outgassing of it and possibly oxidiation of it (to chlorate) in the ozonator at the lower CYA level

I've noticed a spate of "itch" complaints and all so far have started after one or more months of Dichlor use with the critical CYA being around 100 or more when problems started to occur (with FC of around 3 ppm). It's way, way too early to say this is definitive and it certainly doesn't say whether this means this is when hot tub itch occurs or that the higher monochloramine is what irritates. We'll only really know for sure when more people start managing their CYA levels and we see if the number of itching incidents declines (it still might not get eliminated since there are multiple sources for itching, but if we can just reduce the likelihood then I'd say we're making progress).

Richard