Rash, Doesn't Appear To Be Folliculitis, Could It Be Low Ta?

[RPM]

Hello all. For starters, I started reading this forum once I decided to get a hot tub and it has been endlessly helpful. Thanks for all of the information.

I use my hot tub on average once a day. I have no issues until about 1 to 1.5 months after a water change . At that time, I get an itch rash under my arms and on the side of my torso. If I change the water(including a scrub down with a bleach solution), the issue goes away for 1-1.5 months again. My brother lives next door and uses the hot tub just as much. Two friends use the spa less frequently but sometimes 2-3 days in a row. No rash for any of them. I originally thought it was the non-chlorine shock but I have since stopped using it and now use bleach. My levels are as follow(tested with a Taylor K2106):

CH: 290ppm

TA: 40ppm

Ph: 7.4-7.6

Bromine: 3-6ppm

Ozonator

Upon refill, I balance the Ph, CH, and add a packet of sodium bromide to establish the bank. I have a floater to maintain the bromine at 3-6ppm and shock with 1cup of bleach once a week. This maintains +10ppm for about 1 hour.

One issue i see is that my TA is low. I have read that this can cause skin irritation. The problem with the TA is that when I raise the TA to 90ppm with baking soda, the Ph goes through the roof and ultimately I wind up adding Ph down. By the time I get my Ph down, the TA is back to 40ppm. So, I've stopped raising the TA as it just requires more chemicals (Ph down) to reduce it.

Any ideas? Also, I have read a ton of posts asking similar questions and wound up with various viewpoints. Some say to disregard the TA as long as the Ph is good while others say that TA needs to be correct so I'm trying to sort out which is correct.

Again, I can't thank you all enough for all of the information that I've been able to find on this site.

Ryan

[Roger]

Hello all. For starters, I started reading this forum once I decided to get a hot tub and it has been endlessly helpful. Thanks for all of the information.

I use my hot tub on average once a day. I have no issues until about 1 to 1.5 months after a water change . At that time, I get an itch rash under my arms and on the side of my torso. If I change the water(including a scrub down with a bleach solution), the issue goes away for 1-1.5 months again. My brother lives next door and uses the hot tub just as much. Two friends use the spa less frequently but sometimes 2-3 days in a row. No rash for any of them. I originally thought it was the non-chlorine shock but I have since stopped using it and now use bleach. My levels are as follow(tested with a Taylor K2106):

CH: 290ppm

TA: 40ppm

Ph: 7.4-7.6

Bromine: 3-6ppm

Ozonator

Upon refill, I balance the Ph, CH, and add a packet of sodium bromide to establish the bank. I have a floater to maintain the bromine at 3-6ppm and shock with 1cup of bleach once a week. This maintains +10ppm for about 1 hour.

One issue i see is that my TA is low. I have read that this can cause skin irritation. The problem with the TA is that when I raise the TA to 90ppm with baking soda, the Ph goes through the roof and ultimately I wind up adding Ph down. By the time I get my Ph down, the TA is back to 40ppm. So, I've stopped raising the TA as it just requires more chemicals (Ph down) to reduce it.

Any ideas? Also, I have read a ton of posts asking similar questions and wound up with various viewpoints. Some say to disregard the TA as long as the Ph is good while others say that TA needs to be correct so I'm trying to sort out which is correct.

Again, I can't thank you all enough for all of the information that I've been able to find on this site.

Ryan

How often do you use the tub and have you considered Exyma?

[RPM]

How often do you use the tub and have you considered Exyma?

I use the hot tub once a day on average, sometimes twice. I have not considered Eczema but I will be researching it now. I'm skeptical that it's eczema because it takes 1-1.5 months after a water change before it starts(closer to 1.5). I'll update once I get more info.

Thanks

Ryan

[Hillbilly Hot Tub]

Hello all. For starters, I started reading this forum once I decided to get a hot tub and it has been endlessly helpful. Thanks for all of the information.

I use my hot tub on average once a day. I have no issues until about 1 to 1.5 months after a water change . At that time, I get an itch rash under my arms and on the side of my torso. If I change the water(including a scrub down with a bleach solution), the issue goes away for 1-1.5 months again. My brother lives next door and uses the hot tub just as much. Two friends use the spa less frequently but sometimes 2-3 days in a row. No rash for any of them. I originally thought it was the non-chlorine shock but I have since stopped using it and now use bleach. My levels are as follow(tested with a Taylor K2106):

CH: 290ppm

TA: 40ppm

Ph: 7.4-7.6

Bromine: 3-6ppm

Ozonator

Upon refill, I balance the Ph, CH, and add a packet of sodium bromide to establish the bank. I have a floater to maintain the bromine at 3-6ppm and shock with 1cup of bleach once a week. This maintains +10ppm for about 1 hour.

One issue i see is that my TA is low. I have read that this can cause skin irritation. The problem with the TA is that when I raise the TA to 90ppm with baking soda, the Ph goes through the roof and ultimately I wind up adding Ph down. By the time I get my Ph down, the TA is back to 40ppm. So, I've stopped raising the TA as it just requires more chemicals (Ph down) to reduce it.

Any ideas? Also, I have read a ton of posts asking similar questions and wound up with various viewpoints. Some say to disregard the TA as long as the Ph is good while others say that TA needs to be correct so I'm trying to sort out which is correct.

Again, I can't thank you all enough for all of the information that I've been able to find on this site.

Ryan

I just had a class that we talked about the TA issue. I always thought not to worry about it much as long as the PH was ok. What we learned at this class is if the TA is low it makes the water aggresive. It will cause you to go through more chemicals trying to "raise itself"

To raise ALK when PH is good, you have to use PH down to drop PH very low,(which will also drop the ALK) then use ALK first to rasie. The ALK will raise PH also. As you raise the ALK, watch the PH. Get your ALK up as high as you can without bringing the PH over. It is a hard game at times. Having ALK where it belongs helps keep the PH from bouncing around and makes foaming less of an issue.

We were told that people with bromine systems use mostly ALK increaser, very rarely PH increaser becasue the ALK tends to drop in the tub.

Bleach may also be an issue, it is being found in threads on the water chemistry site, that the PH will rise with people that use bleace due to airation of the water. Hot Tubs have a major amount of air going into the water, unless you have a 4 jet oldie. This is also a subject that has various viewpoints.

So, as far as the itch, you may have to see the doc to see what it is from. Maybe low TA, since the water becomes aggresive can be causing an irritation in sesitive skin areas. Since you do not have issues for over a month, I would not think it is a sensitivity to one of the chemicals, that would happen right away. If your TA is good at start up and it is when the TA starts to drop that you have the itch, I would start there.

[chem geek]

Ryan,

You are essentially using a bromine system with a bromide bank, a bromine floater, and used to use MPS to shock and now use chlorine (bleach) for shocking, but it's still a bromine sanitation system. Some people are sensitive to bromine, but it is odd that this only seems to occur for you after 1.5 months (for some Bromine sensitivity users, it's almost right away, but others have reported it later on as you are) as that is sometimes seen with Dichlor which has a logical explanation (buildup of CYA). The bromine feeder does add a chemical along with the bromine (and chlorine, depending on the type of bromine tablet) called 5,5-dimethylhydantoin. It's possible either that you have a sensitivity to this chemical, but only under higher concentrations, or that this chemical may have a CYA-like effect typing up bromine (though the chemical literature gives no indication of that), or that something else is building up in the water giving you skin sensitivity.

Can you take a look at the table in this post and see if you can categorize your rash as being chemical vs. bacterial? It's not an absolute diagnosis, but any information to sort this out can be helpful.

Hillbilly Hot Tub,

Can you give me more information about what you learned about TA in your class? The idea of water being more aggressive with low TA is the same concept as with low pH and low CH where "aggressive" means a stronger tendency to dissolve calcium carbonate and calcium oxide as with plaster/gunite/grout. Low TA is, of course, a lower level of buffering so that it takes smaller amounts of acid or base to move the pH so in that sense the water is more "sensitive" to chemical changes affecting the pH, but the low TA in and of itself only chemically affects the calcium carbonate saturation. Remember that TA is nothing more than a measurement of all chemical species (ions) that can accept hydrogen ions (down to a pH of 4.5). It is measuring the buffer capacity of the water to prevent a drop in pH. In pool and spa water, it mostly measures the amount of bicarbonate in the water -- essentially the amount of carbonation of the water.

I looked at a bunch of water quality reports and find that the alkalnity tends to be in the range of 50-80 ppm and since people take showers or baths, I don't think the lower TA is a cause for irritation. Nevertheless, having Ryan increase the TA to where it was at startup is certainly very easy to try so I'm not disagreeing with your advice and we may learn something new.

Richard

[Hillbilly Hot Tub]

Ryan,

You are essentially using a bromine system with a bromide bank, a bromine floater, and used to use MPS to shock and now use chlorine (bleach) for shocking, but it's still a bromine sanitation system. Some people are sensitive to bromine, but it is odd that this only seems to occur for you after 1.5 months (for some Bromine sensitivity users, it's almost right away, but others have reported it later on as you are) as that is sometimes seen with Dichlor which has a logical explanation (buildup of CYA). The bromine feeder does add a chemical along with the bromine (and chlorine, depending on the type of bromine tablet) called 5,5-dimethylhydantoin. It's possible either that you have a sensitivity to this chemical, but only under higher concentrations, or that this chemical may have a CYA-like effect typing up bromine (though the chemical literature gives no indication of that), or that something else is building up in the water giving you skin sensitivity.

Can you take a look at the table in this post and see if you can categorize your rash as being chemical vs. bacterial? It's not an absolute diagnosis, but any information to sort this out can be helpful.

Hillbilly Hot Tub,

Can you give me more information about what you learned about TA in your class? The idea of water being more aggressive with low TA is the same concept as with low pH and low CH where "aggressive" means a stronger tendency to dissolve calcium carbonate and calcium oxide as with plaster/gunite/grout. Low TA is, of course, a lower level of buffering so that it takes smaller amounts of acid or base to move the pH so in that sense the water is more "sensitive" to chemical changes affecting the pH, but the low TA in and of itself only chemically affects the calcium carbonate saturation. Remember that TA is nothing more than a measurement of all chemical species (ions) that can accept hydrogen ions (down to a pH of 4.5). It is measuring the buffer capacity of the water to prevent a drop in pH. In pool and spa water, it mostly measures the amount of bicarbonate in the water -- essentially the amount of carbonation of the water.

I looked at a bunch of water quality reports and find that the alkalnity tends to be in the range of 50-80 ppm and since people take showers or baths, I don't think the lower TA is a cause for irritation. Nevertheless, having Ryan increase the TA to where it was at startup is certainly very easy to try so I'm not disagreeing with your advice and we may learn something new.

Richard

Alkalinity

Total alkalinity is the measure of the amount of alkaline buffers (primarily carbonates and bicarbonates) in your water. These alkaline substances buffer the water against sudden changes in pH. Total alkalinity is considered the key to water balance. It is the first parameter you should balance when making routine adjustments to your water.

If you neglect to check the total alkalinity in your pool or spa, you may have trouble balancing the pH. You may also notice that pH fluctuates suddenly despite your best efforts to keep it in the ideal range. If the alkalinity is too low, anything introduced to the water will have an immediate impact on pH. Abrupt shifts in pH can cause scaling or corrosion of metal equipment and fixtures as well as other problems. When the total alkalinity is high, the pH has a tendency to drift upward, causing scale to form.

Maintaining an ideal level of alkalinity will protect your pool or spa and its equipment from the harmful effects of sudden pH fluctuations. Think of the alkalinity as training wheels: it keeps the pH in balance without allowing it to tip too far to either side. Of course the pH can still drift upward or downward, but that change will happen gradually as long as the alkalinity falls within the ideal range. The ideal range of total alkalinity for pools and spas is between 80 and 120 ppm (mg/L).

He went on in this discussion to say low ALK is aggressive, it will try to draw from other things, even in acrylic spas. He also said because it was more aggressive it would cause you to chew up more bromine etc. So my thoughts for Ryan with what I learned, is if ALK is to low, he introduces sweat and other contanimates in water, it would have an immediate impact on PH which could cause skin sensitivity. Just a thought and cheap and easy thing to try first. These classes to not get into the technical chemistry, we only have 4 hours and not time to do a whole college coarse, so I am sure it is "watered down" quite a bit. I have taken many, many classes and have always learned/heard new information.

[chem geek]

He went on in this discussion to say low ALK is aggressive, it will try to draw from other things, even in acrylic spas. He also said because it was more aggressive it would cause you to chew up more bromine etc. So my thoughts for Ryan with what I learned, is if ALK is to low, he introduces sweat and other contanimates in water, it would have an immediate impact on PH which could cause skin sensitivity. Just a thought and cheap and easy thing to try first. These classes to not get into the technical chemistry, we only have 4 hours and not time to do a whole college coarse, so I am sure it is "watered down" quite a bit. I have taken many, many classes and have always learned/heard new information.

The first part (that I don't quote above) makes sense chemically, but the latter parts about low alkalinity (by itself) being aggressive and drawing from other things does not except as noted earlier about calcium carbonate and calcium oxide. Unless the pH gets too high or low, then the low alkalinity just means low bicarbonate (mostly, and low carbonate as well) and these are not substances that are in acrylic spas and I can't find anything describing water low in carbonates (alkalinity) degrading acrylics. Low pH I can see having an effect and there's been some talk about low CH (or low saturation index) affecting the gel-coat on some materials (waterbear knows more about that) but the detailed chemistry of this and clear verification of it is not confirmed. I have read about some gel-coat finishes having a calcium carbonate backing to provide strength so in that case the combination of calcium and carbonate levels to provide saturation would be important, but it's not just TA that would be needed in that case, but the combination of CH and TA at a certain pH (and temp and TDS, to a lesser extent). Did the instructor mention the need for calcium carbonate saturation -- that is, having a near-zero saturation index similar to what is done in plaster pools?

In Ryan's case, the high CH of 290 ppm means that even with a low TA of 40 ppm the saturation index is around -0.2 (at 104F) which is not aggressive and in fact is about where you want to be to prevent scaling in the gas heater. However, the general point that a low TA combined with a low CH makes the water aggressive with respect to calcium carbonate or calcium oxide is very true. If Ryan increases his TA to 80 ppm, then the saturation index will be between 0.1 and 0.2 so if the pH were to rise as well, then scaling in the gas heater (where the saturation index would be closer to 0.4 at a pH of 7.5) might slowly start to occur (similar to what you saw in an earlier post where we ran the calculations for the saturation index that "predicted" scaling conditions).

The part about being more aggressive chewing up more bromine doesn't make chemical sense. There is no chemistry going on between alkalinity (carbonates) and bromine. If you want to send me a PM with a contact to this guy, I'd be happy to talk to him to find out exactly what he is talking about regarding these two points (low TA aggressiveness as opposed to general saturation index aggressiveness and low alkalinity consuming bromine).

Richard

[RPM]

Your replies are greatly appreciated.

HHT, I have tried to gradually take the TA up but any adjustment seems to shoot the Ph up even more. I have also tried to lower the pH then raise the TA but the TA winds up going lower with the pH so the net is the same, low TA for the correct pH.

Also, the current levels 40ppm TA and 7.4-7.6 pH are without treatment. This is straight from the tap. I increase the the CH from ~70ppm to 290ppm and add the sodium bromide and floater.

Chem, I would have to say that the rash fits more into the first column, chemical reaction, based on the time to first reaction, duration (the rash improved greatly if I stay out of the tub for 2 days or so), and the reaction on re-exposure.

When this first occurred, I went on Cipro for a cycle as we suspected folliculitis. This was months ago and did not have an effect on the rash.

I could try a switch to chlorine but I would prefer to stay with bromine if possible.

I really enjoy the hot tub on a nightly basis and it's very troubling that this happens. I'm stubborn though and I battle through the itch for my hour or so each night. I also did a water change yesterday and I am back up to temp and good balance except for the low TA. I'll update once I go in and let you know if the symptoms go away with the new water like they did last time.

Thanks again and let me know if any more info would help.

Ryan

[Hillbilly Hot Tub]

Did the instructor mention the need for calcium carbonate saturation --

Richard

Yes he did, I added this in the water chemistry section. I will see if it is ok with him to give his email to you.

[RPM]

I just read your more recent replies and figured the temp may help. I have been keeping the tub at 102 F in the winter months. I'll probably drop to 99 or 100 once it warms up a bit.

[Hillbilly Hot Tub]

In Ryan's case, the high CH of 290 ppm means ........

Richard

Richard, If he does not raise his CH as high (he said he raised it to that) would his ALK come up easier, would CH effect this?

[chem geek]

Richard, If he does not raise his CH as high (he said he raised it to that) would his ALK come up easier, would CH effect this?

I don't believe one has anything to do with the other in terms of ease of adjustment. Just adding baking soda should raise the TA level independent of the CH. The only time I could see raising the TA not resulting in the expected rise in TA would be if the water was already over-saturated with calcium carbonate (i.e. high saturation index) and precipitated calcium carbonate when you added more baking soda for TA. In fact, I've seen this effect in my pool if I add sodium carbonate (pH Up) too quickly since this causes both the pH and the TA (carbonates) to get too high locally, resulting in "clumps" of calcium carbonate forming. They eventually dissolve unless the water is too over-saturated.

The other time when adding baking soda wouldn't raise the TA in an expected way would be if the pH were very, very low in which case adding it would result in rapid outgassing of carbon dioxide as happens when you add baking soda to vinegar (or vice versa), but that's pretty extreme and not seen in normal pools or spas since the pH should not be that low.

As for whether it makes more sense to have the TA raised if the CH is lower, then yes, if one needs calcium carbonate saturation. So if we assume that the gel-coat needs it (similar to plaster), then one wants the TA, CH, pH (at a given temp and TDS) to be balanced to be a slightly negative saturation index, though one does not need to be perfect at this as there is a lot of leeway before water gets really aggressive or scaling occurs (nevertheless, it did seem to predict situations you saw in the heater reasonably well). The higher temperature of spa water means that there is a greater tendency towards scaling than in cooler water such as found in pools. So for the same pH (say, 7.5), you want the TA and/or CH to be lower than would normally be found in cooler pool water. The following combinations all have a saturation index close to -0.2 and a pH of 7.5 and all TA measurements assume no CYA (so if you have CYA in the water, then subtract one-third of its ppm to get the following adjusted TA measurement).

TA ... CH (at pH 7.5, temp 104, TDS around 500)

170 .. 50

95 .. 100

65 .. 150

50 .. 200

40 .. 250

35 .. 300

The above is why one doesn't want nor need very much calcium in their spa, even if they wanted to get closer to calcium carbonate saturation. Compare this to what happens in a pool at a temperature of 82F to get the same -0.2 saturation index

TA ... CH (at pH 7.5, temp 85, TDS around 500)

290 .. 50

145 .. 100

100 .. 150

75 .. 200

60 .. 250

53 .. 300

Remember that the above is for a saturation index of -0.2, not 0.0, so the TA numbers are lower than the "standard" recommended. The NSPI standard midpoint values of 100 ppm TA (with 40 ppm CYA so adjusted TA is 87 ppm) and 300 ppm CYA result in near-zero saturation index for 82F. A gas heater isn't on as often in a pool, so targeting a saturation index closer to 0 instead of -0.2 for a pool is perfectly reasonable and remember that there's a lot of leeway (and measurement error) anyway. In my own pool, I tend to shoot slightly negative since we do use the gas heater a decent amount at the start and end of the season to help with the solar heat.

Richard

[chem geek]

HHT, I have tried to gradually take the TA up but any adjustment seems to shoot the Ph up even more. I have also tried to lower the pH then raise the TA but the TA winds up going lower with the pH so the net is the same, low TA for the correct pH.

Chem, I would have to say that the rash fits more into the first column, chemical reaction, based on the time to first reaction, duration (the rash improved greatly if I stay out of the tub for 2 days or so), and the reaction on re-exposure.

Ryan,

Thanks for the info. I suppose it's possible you have a reaction to higher levels of 5,5-dimethylhydantoin (DMH) or to something else building up in the water over time. Hopefully someone can suggest something for you -- at this point, an early water change seems to be the only solution.

As for adding baking soda to raise the TA, in a 350 gallon tub if you added 1.6 ounces weight or around 8 teaspoons of baking soda, then that should raise the TA by 20 to go from 40 to 60 and should raise the pH from 7.5 to 7.6, so in theory it shouldn't be very much. If you then added even a third of a teaspoon of dry acid, then the pH would drop to 7.5 and the TA would barely budge. Again, that's in theory. As the TA gets higher, the rate of carbon dioxide outgassing will increase and that will make the rate of pH rise faster, but I'm not clear if that is what you are seeing since the yo-yo effect shouldn't happen very much if you are adding sodium bicarbonate (but could happen quite a bit if you are adding sodium carbonate instead).

What exactly were you using to raise the TA? Was it baking soda or a spa product and if the latter, what does it say in the ingredients?

Richard

[dave nh]

Ryan,

you should consider having your rash looked at by a dermatologist, i thought i had ringworm and/or hot tub itch and thought for sure thats what it was. had it on my lower legs and arms. very itchy.

The Doctor took one look at it and said it was eczema. He said the winter tima and taking too hot a shower as well as combining it with a hot tub was not good. Turning down the temperature in the shower is tough and same for the hot tub, but it has helped. Not sure if this is your case but wanted to share, good luck and i hope things work out.

[dave nh]

Ryan,

you should consider having your rash looked at by a dermatologist, i thought i had ringworm and/or hot tub itch and thought for sure thats what it was. had it on my lower legs and arms. very itchy.

The Doctor took one look at it and said it was eczema. He said the winter tima and taking too hot a shower as well as combining it with a hot tub was not good. Turning down the temperature in the shower is tough and same for the hot tub, but it has helped. Not sure if this is your case but wanted to share, good luck and i hope things work out.

[RPM]

Richard,

I will try to raise the TA a bit again. It's certainly worth a try. I use A&H baking soda to do this.

Mine is ~450 gallons so I'm thinking around 2oz weight which should be around 10 teaspoons.

I then use 100% Sodium Bisulfate pH down. It looks like I need somewhere around .4 teaspoon to equal what you quoted for 350 gallons. Should the Sodium Bisulfate lower the TA as well? I'm reading conflicting info on that. If not, I should be able to regulate my TA to correct levels but it seems that when I get the TA to 90ppm, the pH is off the chart. When I lower the pH to 7.5 with the Sodium Bisulfate, the TA winds up down around 40ppm again.

I just referenced my Taylor guide and they have Sodium Bisulfate as the chemical to lower both pH and TA. It's like I'm in a tug of war between TA and pH????

Your time is appreciated.

[RPM]

Dave,

Thanks for the suggestion. I made an appointment last time but dermatologists are scheduled way out. The rash went away when the water was changed so I canceled the appointment. I did the Cipro with my family doctor. I guess I should try the dermatologist route again. I definitely do have dry skin in the winter and the condition gets worse with a hot shower. The odd thing to me though, if it were from dry skin/heat of the tub/shower, why the 1.5 month delay after a water change?

Was there any other remedy other than lowering the temp?

I will look into making another appointment as well.

Thanks,

Ryan

[chem geek]

I know this can get confusing with acid lowering pH and TA, because, well, it is confusing. However, the simple answer is that baking soda raises the TA with a very small rise in pH (unless the pH is starting out low) while acid lowers the pH quite a bit but lowers the TA moderately. So the net result between the two when keeping the pH constant is a net rise in TA.

The advice of using acid to lower the TA is just plain wrong. Some have called this the "slug method" or "acid column", but it simply does not work by itself. A full technical debunking including experiments are described here.

The only way to lower TA (without permanently lowering the pH) is to remove the carbon dioxide from the water via aeration. Since carbon dioxide outgasses faster at lower pH, the procedure to lower TA is to first add acid to lower the pH to around 7.0 or the next to lowest measurement setting on the pH test kit (so 7.2 if the kit only goes down to 7.0) and then aerate. The pH will then rise and acid should be added to keep the pH down while continuing to aerate. This process will cause the TA to drop. When the TA reaches the point you want, you stop adding acid and just continue to aerate until the pH climbs to where you want it. This procedure is described in this post.

You'll have to decide between what Hillbilly Hot Tub is saying (based on his most recent education) and what I'm saying in terms of where you want your CH and TA. Just note that your CH is higher than found in most spas and your saturation index is already pretty high so on that basis if you increased your TA too much then I believe the water could start to scale, especially if the pH were to go up for whatever reason. If your CH wasn't already pretty high (for a spa at higher temps), then I'd see no problem with a "standard" TA level. At any rate, your going from 40 to 60 will just raise the saturation index (at pH 7.5) from -0.15 to +0.03 so isn't a big deal. Raising the TA to 100, however, raises the index to +0.25 -- not serious, but if the pH rose then that plus the higher heat in the gas heater *might* lead to scaling in the heater.

Richard

[dave nh]

Dave,

Thanks for the suggestion. I made an appointment last time but dermatologists are scheduled way out. The rash went away when the water was changed so I canceled the appointment. I did the Cipro with my family doctor. I guess I should try the dermatologist route again. I definitely do have dry skin in the winter and the condition gets worse with a hot shower. The odd thing to me though, if it were from dry skin/heat of the tub/shower, why the 1.5 month delay after a water change?

Was there any other remedy other than lowering the temp?

I will look into making another appointment as well.

Thanks,

Ryan

I know i waited a month to get an appointment, but it was worth it. He prescribed a special ointment to put on the rash areas and it went away and stopped itching pretty quickly. I did start lowering the temperature in the shower and not being in as long, did not really lower my hot tub temp. It could be your water, but it also just might be a coincidence about the water change especially if it is not affecting others.

[RPM]

Hello all,

It's been a week since the water change so I figured I would post an update. The rash has gone away even though I continue to use the tub daily. Richard, I tried to raise the TA and lower the pH as suggested but it took more to lower the pH so I wound up with a TA of 50ppm instead of the original 40. I guess the good news is that a water change after about 1.5 months seems to correct the issue. I'm also going to try to increase the filter cleanings this go around and see what happens.

I think Dave may be on with the dry skin in the winter issue. I'm thinking that the 1.5 months allows enough chemical buildup to irritate my skin. I'll continue to update this thread as I get more information.

There are very few message boards that I subscribe to and this is one of them. It's amazing how much valuable information there is to be shared when you have a group of people that are passionate about a subject. I thank you all again for all of the info that I've taken from this board.

Ryan

[chem geek]

Ryan,

Thanks for the update and glad to hear that the rash has gone away. So instead of going from 40 to 60 in TA you ended up with 50 -- I suspect the additional acid you needed to lower the pH was partly due to outgassing of CO₂. That just means that next time you adjust the TA you can overcompensate for this a little by increasing the baking soda amount. A difference in 10 in TA is in the range of measurement error and when you are doing fine adjustments you need to use your best judgment and experience, but at the end of the day it's not a big deal.

Be sure to check your pH periodically to get a sense of its variability. The main problem with the lower TA is that the pH can swing more readily. In your situation, you need a lower TA than most due to your higher CH so you just need to watch the pH. It doesn't have to be rock solid, but if you can see that it's in the 7.2 - 7.8 range most of the time then that should be fine, where in your situation lower is better (i.e. 7.2 - 7.5 is better) to avoid possibility of scaling. Just get a feel for your hot tub and then relax.

Richard

[mhydamacka]

Hello. I have a similar problem. A rash that is not "hot tub rash" and no one else in my family gets it.

Mine is almost like "welts" and started 4 weeks into us getting our new hot tub. I changed the water on Sunday and used it Monday and Tuesday and now my rash is back worse than ever.

What did the Dr say your rash was from and what did he prescribe.

I am wondering if Low TA is part of the problem with my rash as well.

I have had to wait up to 3 weeks at a time to use it because after waiting a week or two the rash just flared up within hours.

My Dr suggested it being an allergic reaction but the cream he gave me does not seem to work and allergy/benadryl medicine doesn't seem to help much either.

Showering well after using the spa and using a moisturizing sensitive skin soap does seem to help some.

Super frustrating as I would like to use the spa with the rest of my family.

Please, what did your Dr diagnose and give you?

[Dr. Spa]

Psoriasis, eczema and Grovers disease are all possibilities. If your Dr. only suggested, I would suggest finding a new doctor...preferably a board certified dermatologist that's will to spend the time properly diagnosing you.