Itchy rash. What to do with hot tub water?

[davesurfer]

So I've had the hot tub online since the middle of October with no issues, crystal clear water, checking water all the time. In the last couple weeks I noticed some itchy red dots on the insides of my biceps and my sides. They got worse and turned into a really itchy rash type thing. I haven't gone in to the tub for almost a week, and after antihistamines it's almost gone now.

My wife goes in the same amount as I do but didn't get anything. The doctor says those areas of the body the skin is most sensitive so that's why I got the itchiness there. She figured it might be the hot tub. In the last several weeks I've been testing with new test strips (I know, I should get the really good test kit...) that show the stabilizer levels, or cyanuric acid? If I'm reading it right, it's definitely between 150-300 and a very deep purple. Is this what is causing irritation? So when these levels get high the only thing to do is to drain all or part of the tub and replace with fresh water right? I didn't know that would build up so fast! It's only been a couple months and I thought tubs could go for 4-6 months before being drained and refilled etc.

Please help with ideas, my other stats are as follows:

PH 7
FCl 5-10
TA 120
CY 150-300

Thanks!!!

 

[tim5055]

I would recommend two things:

1. Get an accurate test kit.

2. Follow these instructions : How do I use Chlorine in my Spa (or pool)?

Test strips are generally useless so I doubt if anyone here will provide direction based on their results. Order a TF100 and at least include the XL option. That will give you what you need while you are clearing the pool, and probably enough reagents for a couple of years normal use.

The only other real option for a test kit is a Taylor K-2006. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want. Even then it is a little short on the reagent & powder for the FAS/DPD test.

Do you have a pool as well as the hot tub? I generally drain my hot tub into the pool every 3-4 months and start over fresh in the tub.

 

[JoyfulNoise]

How are you chlorinating your spa? Are you using chlorine or bromine or something else?

If you are using chlorine in your spa and your CYA is truly that high (it could be higher, who knows with "guess"strips), then your water has little to no free, active chlorine (hypochlorous acid) to disinfect with. That rash is a good indication that your water has probably got a pretty good bacteria load in it with pseudomonas (hot tub rash) likely present.

You should definitely be getting yourself a MUCH better testing kit than strips (they are worthless) and you should definitely read the sticky that tim5055 posted. As well, since you could have a bacteria problem and, possibly a biofilm issue in your plumbing, I would also recommend you treat your hot tub with a biofilm remover product like Ahh-some. You can use your current water to do the Ahh-some treatment and then dump it and do a fresh fill.

Please post details of the chemicals you have been using and how you have been using them.

 

[JoyfulNoise]

To the OP-

Another issue you could possibly be facing aside from bacterial contamination is the build up of combined chloramines (CC). These are oxidation by-products of bather waste and chlorine. With a CYA level so high, there is very low concentration of active chlorine (hypochlorous acid) in the water. Therefore the complete oxidation of bather waste will be slow and you can build up CCs in your water. CCs can be very irritating to sensitive skin as well as the mucous membranes of the nose and eyes. Unfortunately your test strips do not measure CCs. This is why it is exceedingly important to have a good high quality test kit as that is the only way to measure CCs with any accuracy.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[davesurfer]

To the OP-

Another issue you could possibly be facing aside from bacterial contamination is the build up of combined chloramines (CC). These are oxidation by-products of bather waste and chlorine. With a CYA level so high, there is very low concentration of active chlorine (hypochlorous acid) in the water. Therefore the complete oxidation of bather waste will be slow and you can build up CCs in your water. CCs can be very irritating to sensitive skin as well as the mucous membranes of the nose and eyes. Unfortunately your test strips do not measure CCs. This is why it is exceedingly important to have a good high quality test kit as that is the only way to measure CCs with any accuracy.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

Ah yes, this makes the best sense as well and confirms what my local hot tub store is also saying. The problem is I'm not gassing the hot tub after shocking it, I leave the cover on, so build of CC can't escape and eventually condense back into the water. Apparently this can be quite the irritant like you say. I just shocked it right now and am leaving the cover off for an hour. I'll probably drain about 6 or so inches of water and replace it too to get the CYA levels down. Does this make sense?

 

[Casey]

You will have to drain more than 6" of water in the tub to bring the CYA down to a decent amount. It is certainly a starting point though.

 

[Leebo]

Ive done some cleanup in this thread and have removed some "questionable" advice to the OP. I ask that if you wish to further discuss some of the topics and advice given in this thread you please start a new thread to discuss.

To the OP.........two quick questions for you.

• How does your water look?
• How are you adding chlorine?

 

[JoyfulNoise]

There are 3 main sources of "rash"-like symptoms that can happen in a hot tub -

1. Low sanitizer levels leading to the formation of biofilms in the plumbing and the possibility of bacterial pathogens, eg, pseudomonas ("hot tub itch");
2. Build up of bather waste without sufficient oxidation leading to excess combined chloramines (CC) in the water. CC's are known irritants.
3. "Sensitive" skin that is mechanically damaged by excessively strong spa jets. This can happen and lead to rash-like outbreaks especially in people with known skin disorders like eczema or psoriasis where mechanical abrasion and the ensuing inflammatory response can cause an outbreak of lesions

Based on what was written previously, #2 seems the most likely as the OP has both excessive CYA levels (therefore low chlorine oxidation rates) AND keeps the hot tub covered which does not allow any CC's generated to outgas. The primary problem here is that we do not have definitive water chemistry information as the OP only has access to test strips which are very ineffective at best. I realize that the OP lives in Canada and so access to a quality Taylor test kit is going to be expensive. However, I would stress that, without good water test results, it will be exceedingly difficult to determine the exact cause of the problem.

To the OP -

Can you please answer Leebo's questions and let us know what chemicals you are using in your hot tub. It sounds like your water is several months old and that your CYA is excessively high. This may be the time where you just have to drain the hot tub and refill it. If the Ahh-some jetted hot tub cleaner product is available to you in Canada, it would be advisable to regularly use it to clean out your tubs plumbing especially if it has never been cleaned before.

 

[davesurfer]

Ive done some cleanup in this thread and have removed some "questionable" advice to the OP. I ask that if you wish to further discuss some of the topics and advice given in this thread you please start a new thread to discuss.

To the OP.........two quick questions for you.

• How does your water look?
• How are you adding chlorine?

Water has always been and is very crystal clear. No foam either. I'm adding chlorine using the floating dispenser, but with the occasional shock treatment every other week or so when I notice the free chlorine getting low, but I wasn't leaving the cover off to gas it though.

 

[JoyfulNoise]

Water has always been and is very crystal clear. No foam either. I'm adding chlorine using the floating dispenser, but with the occasional shock treatment every other week or so when I notice the free chlorine getting low, but I wasn't leaving the cover off to gas it though.

What are the listed chemical names for the tablets you add to the dispenser and the shock powder you add every other week?

 

[davesurfer]

There are 3 main sources of "rash"-like symptoms that can happen in a hot tub -

1. Low sanitizer levels leading to the formation of biofilms in the plumbing and the possibility of bacterial pathogens, eg, pseudomonas ("hot tub itch");
2. Build up of bather waste without sufficient oxidation leading to excess combined chloramines (CC) in the water. CC's are known irritants.
3. "Sensitive" skin that is mechanically damaged by excessively strong spa jets. This can happen and lead to rash-like outbreaks especially in people with known skin disorders like eczema or psoriasis where mechanical abrasion and the ensuing inflammatory response can cause an outbreak of lesions

Based on what was written previously, #2 seems the most likely as the OP has both excessive CYA levels (therefore low chlorine oxidation rates) AND keeps the hot tub covered which does not allow any CC's generated to outgas. The primary problem here is that we do not have definitive water chemistry information as the OP only has access to test strips which are very ineffective at best. I realize that the OP lives in Canada and so access to a quality Taylor test kit is going to be expensive. However, I would stress that, without good water test results, it will be exceedingly difficult to determine the exact cause of the problem.

To the OP -

Can you please answer Leebo's questions and let us know what chemicals you are using in your hot tub. It sounds like your water is several months old and that your CYA is excessively high. This may be the time where you just have to drain the hot tub and refill it. If the Ahh-some jetted hot tub cleaner product is available to you in Canada, it would be advisable to regularly use it to clean out your tubs plumbing especially if it has never been cleaned before.

I think it's a bit of 2 & 3. I haven't let the CC gas out when I do the shocking and they are building up. Also I usually spend most of my time sitting with my back to about 6 powerful jets as I really like the massage they give. Now that you say it, that makes a lot of sense too, because the jets hit my back and my sides and the insides of my biceps where the itchy red dots and rash started to form. The doctor says the back has a lot more tougher skin then the other two areas so it wasn't affected.

I'm using tri-chlor pucks in a floating dispenser. You say it sounds like my water is several months old, but that's what confuses me too, because it's not--it was only filled around the middle of October. I have gone through lots of pucks though, and I think I might have been keeping the FCl levels too high, because it's usually a purple to dark purple--maybe that's why a lot of CYA is in the water.

Also regarding the plumbing, when I first filled it in October I used a cleaner for the plumbing, then I drained it again and re-filled it.

 

[pooldv]

Sounds like it would be best to drain, refill and follow this process, How do I use Chlorine in my Spa (or pool)?

I had slight trouble with rashes when I first got my tub. But following this method has been great for 2 years. We use our tub several times per week or more. We also add some epsom salts.

 

[JoyfulNoise]

I think it's a bit of 2 & 3. I haven't let the CC gas out when I do the shocking and they are building up. Also I usually spend most of my time sitting with my back to about 6 powerful jets as I really like the massage they give. Now that you say it, that makes a lot of sense too, because the jets hit my back and my sides and the insides of my biceps where the itchy red dots and rash started to form. The doctor says the back has a lot more tougher skin then the other two areas so it wasn't affected.

I'm using tri-chlor pucks in a floating dispenser. You say it sounds like my water is several months old, but that's what confuses me too, because it's not--it was only filled around the middle of October. I have gone through lots of pucks though, and I think I might have been keeping the FCl levels too high, because it's usually a purple to dark purple--maybe that's why a lot of CYA is in the water.

Also regarding the plumbing, when I first filled it in October I used a cleaner for the plumbing, then I drained it again and re-filled it.

OK. So there's a couple of things here that stand out.

First, if we assume we can trust your strips somewhat, you CYA is effectively off the charts and is probably causing the bulk of the problems. CYA is a chlorine buffer, that is, it holds chlorine in reserve and actually lowers the active chlorine (hypochlorous acid) level (active chlorine is different than free chlorine). It's the active chlorine that sanitizes your water and oxidizes bather waste. So if your CYA is too high, your active chlorine level will be too low and pathogens can live in your water. So it's more likely that scenario #1 is your biggest problem right now.

Second, using trichlor in a hot tub is not really advised. Trichlor is not only very acidic but it will also dissolve too quickly and raise both your FC and CYA very fast. Too much trichlor can actually neutralize all of your TA (total alkalinity) and cause your pH to crash to really low values (assuming you are not adding any TA by using baking soda).

If your shock powder is dichlor, well then that is just adding even more CYA to your water and making the active chlorine even less effective. With such a low active chlorine level, it can take much longer than 24 hours for all of the bather waste to get oxidized. Since you are using the hot tub heavily, that means the water is never really getting clean before the next soak.

So, in the end, I think you need to dump the water you have now and try to follow the dichlor-then-bleach method of hot tub maintenance. It will require a little more effort to maintain the FC on your part (daily bleach additions and no more floating tablet dispensers), but your water will be much healthier.

 

[davesurfer]

OK. So there's a couple of things here that stand out.

First, if we assume we can trust your strips somewhat, you CYA is effectively off the charts and is probably causing the bulk of the problems. CYA is a chlorine buffer, that is, it holds chlorine in reserve and actually lowers the active chlorine (hypochlorous acid) level (active chlorine is different than free chlorine). It's the active chlorine that sanitizes your water and oxidizes bather waste. So if your CYA is too high, your active chlorine level will be too low and pathogens can live in your water. So it's more likely that scenario #1 is your biggest problem right now.

Second, using trichlor in a hot tub is not really advised. Trichlor is not only very acidic but it will also dissolve too quickly and raise both your FC and CYA very fast. Too much trichlor can actually neutralize all of your TA (total alkalinity) and cause your pH to crash to really low values (assuming you are not adding any TA by using baking soda).

If your shock powder is dichlor, well then that is just adding even more CYA to your water and making the active chlorine even less effective. With such a low active chlorine level, it can take much longer than 24 hours for all of the bather waste to get oxidized. Since you are using the hot tub heavily, that means the water is never really getting clean before the next soak.

So, in the end, I think you need to dump the water you have now and try to follow the dichlor-then-bleach method of hot tub maintenance. It will require a little more effort to maintain the FC on your part (daily bleach additions and no more floating tablet dispensers), but your water will be much healthier.

Thanks! Ok, not sure how to get a total of 34ppm in there over a few days. "On one day you test your FC and it's 1 ppm. You'll then add 5 ppm FC to bring it to 6." Wasn't sure how to add 5 ppm of FC. I guess it's just trial and error. I do have Chlorox bleach, but it's the "concentrated" kind. Would it be fine to just add the dichlor granules daily after using the spa? Or would this increase the CYA too fast like it did before? I just have no idea how much bleach to add after the CYA is at acceptable levels.

Also, regarding draining, it's about -3/-4 C here, worried about freezing pipes, would it be fine to drain it totally if I started filling it right away? Or maybe I should just drain half of it now? Thanks!

 

[MarianParoo]

Have you ever looked at PoolMath? There is a button for it at the top of the page. That will help you figure out how much of a chemical to add to attain your goals. Take a peek and let us know if you have any questions!

I don't know about your pipes.

 

[davesurfer]

Have you ever looked at PoolMath? There is a button for it at the top of the page. That will help you figure out how much of a chemical to add to attain your goals. Take a peek and let us know if you have any questions!

I don't know about your pipes.

Oh wow, nice calculator I'll be checking this out. Like I said, I did do plumbing cleaning with a cleaner I bought from the hot tub store the first time I filled it, ran the pumps as recommended, drained it and refilled.

 

[JoyfulNoise]

Ahh-some is the best product on the market for tub cleaning. If you can get it in Canada, it is well worth the cost.

As for draining in -4C weather, not sure what to do about that. Perhaps you can get the tub hot and then drain it fully and add back water right away. It would be best to do another clean out (with Ahh-some if possible) using your current "dirty" water and then drain and refill.

Sorry, I live where it's warm and sunny 10 months out of the year and freezing cold temps rarely occur. I left the -4 deg C type weather behind many year ago much to my happiness


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[davesurfer]

Ahh-some is the best product on the market for tub cleaning. If you can get it in Canada, it is well worth the cost.

As for draining in -4C weather, not sure what to do about that. Perhaps you can get the tub hot and then drain it fully and add back water right away. It would be best to do another clean out (with Ahh-some if possible) using your current "dirty" water and then drain and refill.

Sorry, I live where it's warm and sunny 10 months out of the year and freezing cold temps rarely occur. I left the -4 deg C type weather behind many year ago much to my happiness


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

Yeah I was going to refill it right away after draining. It's supposed to be 2 tomorrow, 0 and 1 the following days so that would be fine. I can't find any Ahh Some in Canada, Amazon.ca has non in stock. Plus I'd hate to have to wait weeks for it to come in and not using the hot tub

No I love that we have the 4 seasons here. The cold months are the best for using the hot tub, I wouldn't like using it during hot weather...in hot weather I jump in the lake to cool down It's the best experience to be in the hot tub on a cold clear winter night looking at thousands of stars and maybe feeling a few snowflakes fall down on your face

 

[davesurfer]

Did the dichlor then bleach method after dumping and doing a clean. Seems like the FC gets used up very quickly or something is wrong with the calculations. I went in again after taking a week or so off and the itchy spots and rash came back again very quickly So I don't know what's wrong. I've been using the hot tub since October, the rash thing happened much later so... trying to see where I can buy Ahh-some to see if that will help clean out the plumbing.

 

[pooldv]

I had some trouble early on with adding enough bleach sometimes. Keep adding and testing until the FC holds.