Hot Tub Itch Cured!

[SoCal Hot Tub]

First, I would like to say what an invaluable resource this board is. The information posted by all of the knowledgeable contributors is much better and more thorough than anything I received from local spa retailers.

The issue I had was putting in a spa last summer, over $10,000 for spa, deck, landscaping, etc. First few months everything was great; my wife, kids, and I loved it and used it regularly. Then came the dreaded rash and kinda painful itch, on me only. Called the dealer and was told probably due to low Ph. Corrected the Ph, still itched. Was told nothing about bacteria growth, CYA levels, etc. A google search for "hot tub itch" led me here thankfully. First tried the method of draining the spa, and washing down the tub and cover with a bleach solution and then refilling. No luck, rash reappeared immediately. Needless to say this was very disappointing and discouraging to not be able to use the spa after all the expense and time putting it in.

I read another post here that finally was the "miracle cure" for the itch. The process used was drain the spa completely, wipe down any residue, refill to an inch or two above the normal water line, add bleach to bring the FC up to 20-30 ppm, run spa for a couple of hours with heater off, while also making sure to turn any diverter valves to both extremes to sanitize all areas. I also drained this water afterwards (may have been overkill) and then refilled. Balanced chemicals normally using Dichlor, dry acid, etc. Bought a Taylor test kit (what a difference that makes from using test strips only), stopped using Dichlor after the CYA level reached a level below 30, which is the smallest measurement the kit can register, and then switched to Clorox bleach. NOR MORE RASH OR ITCH!!

A couple of conclusions can be drawn. Information is the key, and it seems the best information does not always come from the local dealer. I was told when I bought the spa to stay on a regimen of checking chlorine every 2-3 days and add 2 tsp if low, shock with non chlorine shock after every use, keep TA up at 150 ppm. I should mention that using this method the first time I tested the CYA level it was way over 100. The dealers method in hindsight is very "cookie cutter" and was not effective for the heavy bather load for me. I think he was emphasizing the simplicity of water care over effectiveness.

It really only takes a few minutes now to balance the water once a day using the Taylor kit, and keeping the FC levels up is a piece of cake if done routinely-once a day during light use, adding 3-4 oz Clorox Bleach after heavy use. Also adding a teaspoon or two of dry acid when needed to bring the Ph down. Very easy and much more effective than the Dichlor only method.

Thanks to all who have posted here and provided such great information. ChemGeek's analysis about chlorine's lack of effectiveness as CYA rises was very informative. After the expense of putting in a spa, I certainly am not using Bleach as the sanitizer to save money; the savings is insignificant, but the effectiveness is beyond doubt.

SoCal Hot Tub, AKA NoMoItch!

[chem geek]

SoCal Hot Tub,

I'm really glad you resolved your problem with hot tub itch. Unfortunately, you can't really tell for sure what the source of the itch was nor what cured it with a single case. Given that you needed to super-shock with chlorine the entire surface of the tub (including above the waterline), it's possible that chlorine-resistant biofilms were present, but again one cannot know for sure. I've been compiling a list of rash/itch cases here so hopefully over time more significant patterns will emerge.

Using the Dichlor for a short time and then switching to bleach is generally too inconvenient for those with an ozonator or other aeration since the pH will rise too quickly, though this can be mitigated by adding acid before adding bleach after each soak (but that's one more thing to add). Do you have an ozonator? How often to you need to add acid? What is your Total Alkalinity (TA) level?

Richard

[104 Degrees]

SoCal Hot Tub,

Using the Dichlor for a short time and then switching to bleach is generally too inconvenient for those with an ozonator or other aeration since the pH will rise too quickly, though this can be mitigated by adding acid before adding bleach after each soak (but that's one more thing to add). Do you have an ozonator? How often to you need to add acid? What is your Total Alkalinity (TA) level?

Richard

Richard

What type of Acid do you use?

[chem geek]

I have a pool, not a hot tub, and the pH is very, very stable (I only use 12.5% chlorinating liquid). I add acid perhaps once or twice a season (and that's just to go from 7.7 to 7.5) and I use Muriatic Acid (31.45% Hydrochloric acid). For a hot tub, it's easier and somewhat safer to use dry acid (sodium bisulfate) though if you were to use Muriatic Acid I would say to use the half-strength variety that's around 15% as it fumes less. Regardless of the type of acid that is used, it is critically important to add it VERY slowly to the spa over a return flow with the pump running (and the jets off to prevent splashing). One should wear protective eye covering as getting any acid into the eye can lead to blindness. Since the quantity you are adding is so small, you can take a small bucket of spa water and add the acid to the swirling water, then slowly add that back to the spa (this is probably being overly conservative).

Acid can cause far more damage than bleach (both to the spa and to yourself) and the concentration of the acid is extremely high. This is why in a pool you should never pour acid into the skimmer, even if you do it slowly. You simply cannot dilute it enough to prevent the pH from going to around 1.5 via the skimmer (the 31.45% strength acid itself has a pH of -1 which is negative due to the logarithmic scale). Over a return flow in the deep end, it can disperse more quickly and the buffering of the pool can handle it when it gets diluted enough (similarly in a spa).

Richard

[SoCal Hot Tub]

Hi Richard:

So far the bleach method instead of Dichlor is very easy. I have a D1 round spa, approx 350 gallons, with an ozonator (at least it's supposed to, not sure what it looks like). I am keeping my TA at about 60 and my Ph at 7.6. If there has been a heavy bather load (more than 1 person for more than say 15 minutes) then I'll add 2-3 oz. of bleach. First thing in the morning I'll check Ph and Chlorine levels and make sure the chlorine is up around 5-6 ppm. Unless the Ph is really high, over 7.9 or 8.0, then I'll put the chlorine in first and Ph down 15 or so minutes later if needed. If the Ph goes above the 7.9 or 8.0, then I'll adjust Ph first. Anywhere from 3/4 to 2 tsp. of Ph down depending on Ph reading from the Taylor kit. Probably every second or third time requires some acid. I personally have not seen any wild Ph swings, up or down, it's pretty predictable how much and when the Ph down is needed. Not rocket science by any means, just consistently checking chem levels every morning-takes all of about 5 minutes.

I absolutely agree with you Richard that many people would rather stick to the convenience of using Dichlor exclusively. I would too, except I am convinced of the lack of sanitizing effectiveness as the CYA levels rise. In my family nobody else was bothered by "the itch" except me (just lucky, I guess). I, for one, think it's well worth the extra 5-10 minutes/day to have a more effective sanitizing method. I realize this is anecdotal, but it is what has worked for me.

Thanks for all the great information,

SoCal Hot Tub

[Tim w]

First, I would like to say what an invaluable resource this board is. The information posted by all of the knowledgeable contributors is much better and more thorough than anything I received from local spa retailers.

The issue I had was putting in a spa last summer, over $10,000 for spa, deck, landscaping, etc. First few months everything was great; my wife, kids, and I loved it and used it regularly. Then came the dreaded rash and kinda painful itch, on me only. Called the dealer and was told probably due to low Ph. Corrected the Ph, still itched. Was told nothing about bacteria growth, CYA levels, etc. A google search for "hot tub itch" led me here thankfully. First tried the method of draining the spa, and washing down the tub and cover with a bleach solution and then refilling. No luck, rash reappeared immediately. Needless to say this was very disappointing and discouraging to not be able to use the spa after all the expense and time putting it in.

I read another post here that finally was the "miracle cure" for the itch. The process used was drain the spa completely, wipe down any residue, refill to an inch or two above the normal water line, add bleach to bring the FC up to 20-30 ppm, run spa for a couple of hours with heater off, while also making sure to turn any diverter valves to both extremes to sanitize all areas. I also drained this water afterwards (may have been overkill) and then refilled. Balanced chemicals normally using Dichlor, dry acid, etc. Bought a Taylor test kit (what a difference that makes from using test strips only), stopped using Dichlor after the CYA level reached a level below 30, which is the smallest measurement the kit can register, and then switched to Clorox bleach. NOR MORE RASH OR ITCH!!

A couple of conclusions can be drawn. Information is the key, and it seems the best information does not always come from the local dealer. I was told when I bought the spa to stay on a regimen of checking chlorine every 2-3 days and add 2 tsp if low, shock with non chlorine shock after every use, keep TA up at 150 ppm. I should mention that using this method the first time I tested the CYA level it was way over 100. The dealers method in hindsight is very "cookie cutter" and was not effective for the heavy bather load for me. I think he was emphasizing the simplicity of water care over effectiveness.

It really only takes a few minutes now to balance the water once a day using the Taylor kit, and keeping the FC levels up is a piece of cake if done routinely-once a day during light use, adding 3-4 oz Clorox Bleach after heavy use. Also adding a teaspoon or two of dry acid when needed to bring the Ph down. Very easy and much more effective than the Dichlor only method.

Thanks to all who have posted here and provided such great information. ChemGeek's analysis about chlorine's lack of effectiveness as CYA rises was very informative. After the expense of putting in a spa, I certainly am not using Bleach as the sanitizer to save money; the savings is insignificant, but the effectiveness is beyond doubt.

SoCal Hot Tub, AKA NoMoItch!

Thanks SoCal

I have a very simalar problem. We have had our tub for about 4 years now and the first 3.5 years were just about perfect with the odd complaint coming from my loving wife about some itching which we think was coming from the odd time the chlorine was a bit high. We then thought perhaps it would be better to use Bromine which we tryed for a few months. This was some what better for a while but over time this became problematic as well, so we switched back to Chlorine and my wifes rashes although rare came back. To reduce the amount of rashes she was getting I reduced the level of Chlorine. Although this seemed to work for a few months I soon developed a rash that I came to know as falliculitis which I'm convinced is right. The problem I have it that if this rash is in fact bacterial them why am I the only one that get's it.

I have tryed every published solution to resolve this because we spent every evening in our tub sipping on a class of wine and

and discussing our day.

Our tub does have an ozonator that is to be some help with the sanitation but I'm thinking it may have quit or for some reason has become inefective.

What I'm now prepard to try in your method with the hopes that it will work and I'll once again be able to enjoy the tub and the discussions with my wife.

It should be noted that I'm *** retentive with my water qualty in my tub and have become obsessed with fixing my water and usinf my hot tub every day again.

I await your thoughts

T

[OttawaGreg]

I have a pool, not a hot tub,

Richard

Richard, I just wanted to be sure on this post you made. You do not operate a hot tub (spa) but have just a pool?

thanks,

Greg

[Nitro]

Tim, did your rash come right after/during soaking, or did it come later? That may give you a clue as to whether it's Bacteria. Bacteria infections usually appears after a couple days. Sensitivity (alergies) comes sooner. Check here for more info.

I recommend doing a Decontamination (see link below). Then using the Dichlor/Bleach method. See below for full instructions. If you still have sensitivity, you can try Nature 2 low (no) Chlorine method.

[chem geek]

Richard, I just wanted to be sure on this post you made. You do not operate a hot tub (spa) but have just a pool?

Yes, that is correct. My pool is here and I do not have a hot tub. That's why I only tend to comment on water chemistry and not on other operational issues.

[Nitro]

Greg, don't think that matters. Richard knows more about Hot Tub water chemistry (chemistry in general) than most people with hot tubs (and/or without).

Richard, just curious, any plans to get a hot tub?

[chem geek]

Richard, just curious, any plans to get a hot tub?

No plans for a hot tub; not sure where we'd put it. We have gone into other people's tubs -- just a few weeks ago we were in a friend's tub in Ashland, Oregon whom we were visiting. Our pool is used as a therapy pool for my wife (she exercises and swims almost every day) so is usually at 88F so is quite warm, though obviously not the same as a hot tub.

[Nitro]

No plans for a hot tub; not sure where we'd put it. We have gone into other people's tubs -- just a few weeks ago we were in a friend's tub in Ashland, Oregon whom we were visiting. Our pool is used as a therapy pool for my wife (she exercises and swims almost every day) so is usually at 88F so is quite warm, though obviously not the same as a hot tub.

What method of sanitation were they using, Dichlor/Bleach?

[OttawaGreg]

Richard, I just wanted to be sure on this post you made. You do not operate a hot tub (spa) but have just a pool?

Yes, that is correct. My pool is here and I do not have a hot tub. That's why I only tend to comment on water chemistry and not on other operational issues.

Right, got it, thanks. BTW nice crystal clear pool there ;-)

[BigDfromTN]

Tim, did your rash come right after/during soaking, or did it come later? That may give you a clue as to whether it's Bacteria. Bacteria infections usually appears after a couple days. Sensitivity (alergies) comes sooner. Check here for more info.

I recommend doing a Decontamination (see link below). Then using the Dichlor/Bleach method. See below for full instructions. If you still have sensitivity, you can try Nature 2 low (no) Chlorine method.

Nitro, NOT questioning your knowledge and help here at all!!!

But, how do you know if it comes up right away or if it took a few days when you soak everyday? Just curious as to how to determine which exposure caused the breakout.

I too have an occasional issue with an itchy rash normally on my legs. I just coat with Hydrocortisone and it clears up. I know I have an allergy to bleach in some circumstances. IE: when I wore briefs and wife would bleach them, I would break out. Now I wear boxers and she dont bleach.!!!

When I got my tub I did the chlorine decon but not the spa flush thing. Chlorine demand is not excessive and I am following your dichlor/bleach method and thank you for sharing the info.

[Tim w]

Tim, did your rash come right after/during soaking, or did it come later? That may give you a clue as to whether it's Bacteria. Bacteria infections usually appears after a couple days. Sensitivity (alergies) comes sooner. Check here for more info.

I recommend doing a Decontamination (see link below). Then using the Dichlor/Bleach method. See below for full instructions. If you still have sensitivity, you can try Nature 2 low (no) Chlorine method.

Thanks Nitro

We have done the Decomtamination process already and tested the process to comfrim it worked. It seemed to because after added chlorine and waiting 24Hrs there was still the residual free chlorine (FC) so I think the procedure worked but the problem was re interduced some how.

THe rash and iching comes a few days after I have used the tub. I appieciate your question about when the rach appears because I was beginning to think that perhaps it was a reaction to the Chlorine but I'm sure now it's not. Because the weather here is quite nice I 'll proceed with the decontamination one more time and will start to use the bleach to see if this resolves the problem. I have had some thoughts about useing bleach in the passed so this idea fits with my thinking.

Any thing to add

[Nitro]

Keep in mind the only way to know for sure is to see doctor (dermatologist).

When you do the decon, make sure you wipe all areas of the spa with the superchlorinated water, cover, pillows etc. It can easily get re-introduced if you're not thorough.

[cofive]

I have a pool, not a hot tub, and the pH is very, very stable (I only use 12.5% chlorinating liquid). I add acid perhaps once or twice a season (and that's just to go from 7.7 to 7.5) and I use Muriatic Acid (31.45% Hydrochloric acid). For a hot tub, it's easier and somewhat safer to use dry acid (sodium bisulfate) though if you were to use Muriatic Acid I would say to use the half-strength variety that's around 15% as it fumes less. Regardless of the type of acid that is used, it is critically important to add it VERY slowly to the spa over a return flow with the pump running (and the jets off to prevent splashing). One should wear protective eye covering as getting any acid into the eye can lead to blindness. Since the quantity you are adding is so small, you can take a small bucket of spa water and add the acid to the swirling water, then slowly add that back to the spa (this is probably being overly conservative).

Acid can cause far more damage than bleach (both to the spa and to yourself) and the concentration of the acid is extremely high. This is why in a pool you should never pour acid into the skimmer, even if you do it slowly. You simply cannot dilute it enough to prevent the pH from going to around 1.5 via the skimmer (the 31.45% strength acid itself has a pH of -1 which is negative due to the logarithmic scale). Over a return flow in the deep end, it can disperse more quickly and the buffering of the pool can handle it when it gets diluted enough (similarly in a spa).

Richard

Richard,

While doing some reading regarding what I believe is an allergy to MPS, I came across some information that stated that if one suspects an allergy to MPS because of the sulfates, the use of dry acid may also be a culprit because of the bisulfate. Any thoughts on this? Also what is the makeup of Muriatic acid?

I am going to do a drain and fill, strictly follow the dichlor/bleach method and avoid any non-chlorine shock products and sodium bisulfate (if possible). I'm crossing my fingers that this will finally resolve the rash issue once and for all.

Ken

[chem geek]

Ken,

Both non-chlorine shock (potassium monopersulfate aka MPS) and dry acid (sodium bisulfate) will add sulfates to the water. I'd be surprised if sulfates were the problem, but then again individual body sensitivity to chemicals runs the gamut. So yes, if you suspect the problem to be sulfates, then don't use either MPS nor dry acid.

Usually when people have a sensitivity to MPS it is due either to the minor but irritating component potassium persulfate (peroxydisulfate) or to MPS itself. This irritating component breaks down quickly when silver ions are present which is why non-chlorine shock is more tolerated in a Nature2 system. Some people may have sensitivity to MPS itself, probably due to its strong, though selective, oxidizing capability.

Muriatic Acid is hydrochloric acid so will not add to sulfates. It will add to chloride, just as all chlorine sources will.

Richard

[cofive]

Here's some interesting reading for those that are suffering like I am. I've emptied and refilled. Will not touch MPS or even dry acid, will subsitute muriatic acid for my Ph lowering needs. I'll keep you posted.

Just did a "peroxymonosulfate allergy" search.

http://www.thepittsburghchannel.com/health...599/detail.html

http://www.wave3.com/Global/story.asp?S=9619668

Ken

[Jdd658]

On 11/30/2009 at 3:58 PM, cofive said:

Here's some interesting reading for those that are suffering like I am. I've emptied and refilled. Will not touch MPS or even dry acid, will subsitute muriatic acid for my Ph lowering needs. I'll keep you posted.

Just did a "peroxymonosulfate allergy" search.

http://www.thepittsburghchannel.com/health...599/detail.html

http://www.wave3.com/Global/story.asp?S=9619668

Ken

Any updates? I’ve been thinking of doing the same exact thing as I’ve been having allergic skin reactions. I’ve narrowed it down to  MPS or muriatic acid. (Tried hotel hot tubs which are usually very chemical and gross and NO reaction!) and my water is pristine on my test strips 

[chrisc0le]

I too get an itch (nothing too bad and usually starts the morning after a soak). 
I thought it might be MPS, but having read this is does make more sense that it could be the dry acid (PH Minus) I used after a refill with zero MPS added.

I will try to acquire some Muriatic acid instead of the dry acid, but as always in the UK the stupidity of others means it's hard to get hold of some chemicals.

Would this do the job? (Hydrochloric Acid 35.0-36.6%).

 

Chris