Hot Tub Itch Confirmed...now What?

[gary3029]

I have read a lot on this forum over past two days about the hot tub itch!! I have had mine confirmed as the real thing. I have come out in sores on my legs, arms, abdomen and back. They look like insect bites and itch like mad. My daughter has also come out in the same spots but thankfully not as bad. I have a hotub which is used about 5 times + a week. I use bromine in a despenser and shock weekly and change the filter. Only problem I thought I had was I forever had a falling PH and despite chemicals and air it was difficult to maintain correctly. TA was alway in normal paremeters. I did note that I could have a zero reading of bromine sometimes despite have tabs in the despenser and I think is the cause of the problem.

In an effort to win the wife over that the hotub is safe I have changed from bromine to dosing with chlorine daily as required to keep the levels at 2-3 ppm. I aim to change the water more frequently so as to deal with the buildup of cya. This will also help reduce different chemicals as I also have a pool.

Can the experts on here advise me of the best housekeeping plan for the hotub and restore my battered confidence. I thought I was doing it right, shows how things can go wrong with a little knowledge. My wife is best not pleased with the sate of my skin and the sleepless nights we are having with my daughter.

regards

gary

[Whoneedsavacation]

I did note that I could have a zero reading of bromine sometimes despite have tabs in the despenser and I think is the cause of the problem.

Definitely, this probably allowed the bacteria to grow. You need to have the bromine level stable within safe limits even if the water looks clear... now that you have switched to chlorine others will be able to advise better, I suspect, I'm a bromine person.

[Whoneedsavacation]

[edited to remove duplicate copy]

[cplarsen]

Chlorine is going to run out on you even faster than bromine, Gary, so now you're really going to have to monitor the tub. Like, every day! Which is fine in this case, it'll keep you more in tune.

And since the wife is p.o.'d, I'd go higher than 3 ppm on the chlorine. More ain't going to hurt, and it's cheap.

To start, superchlorinate ( a fancy way of saying get the chlorine level up to +12 ppm, or throwing in a double dose). That'll get rid of the bacteria you already have. Be sure wipe everything down above the water line with that chlorinated water. Mold likes to hide under those diverter valve controls, btw.

Then, add enough chlorine every day to get your chlorine level up to 5 ppm. (check 15 minutes after adding with test kit) Should be about 3/4 tablespoon of stabilized chlorine, but it'll depend on the brand of chlorine, size of your tub and your water situation. You can add it after use and it'll mostly be gone by the next time you use the tub.

Shock once a week with MPS and you're good to go.

Good page for water care

http://www.rhtubs.com/info/water.htm

[chem geek]

I agree with what was expressed above about needing even more diligence using chlorine than bromine. Also, if you use Dichlor as your sole source of chlorine, then to minimize the risk of getting hot tub itch you will need to change the water more frequently since for every 10 ppm Free Chlorine (FC) added by Dichlor, it also adds 6 ppm to Cyanuric Acid (CYA). The buildup of CYA will make the chlorine less effective as a disinfectant (unless you increased the FC level proportionately which is not practical).

If you don't want to change the water after a month or so, then there is another alternative. After a week of Dichlor usage to build up some CYA, the use of unscented bleach (Clorox Regular or off-brand Ultra) will add chlorine without CYA, but will make pH control harder usually requiring acid addition. If your tub has an ozonator or other significant source of aeration, this would require more acid addition when using bleach. In 350 gallons, 2 teaspoons of Dichlor is roughly 4 ppm FC and is roughly equivalent to 3 fluid ounces of 6% bleach. You can read about one user who uses the Dichlor then bleach method here and there are others doing this as well, but again it is NOT as easy for maintenance and may be too frustrating dealing with the pH depending on your specific system (i.e. if you have an ozonator). In your case, you might be OK since you report pH dropping when using bromine, so perhaps you won't see too much pH rise if you use bleach (after initial Dichlor the first week).

This post shows a table of all reported rash/itch problems, mostly reported on this forum, and the main pattern is having too low or no sanitizer -- either bromine or chlorine -- or longer-term usage after 1-1.5 months. With Dichlor, this is understandable due to the buildup of CYA. With bromine it is unclear of the cause in every case.

Letting the sanitizer level get close to zero is an absolute no-no. It only takes from 15 minutes to an hour for most bacteria to double in population. That's up to an increase in population of over 4 billion in 8 hours if there were no limiting factors. So being lax for just one day is all it takes to have bacterial soup. This is one reason some people use Nature2 or other metal ion systems so that uncontrolled bacterial growth is kept in check even if you forget to add some sanitizer (metal ions kill more slowly than chlorine or bromine, but still fast enough to prevent uncontrolled bacterial growth in most cases). Use of an ozonator can help kill free-floating bacteria, but won't do anything for bacteria stuck to surfaces in biofilms. If you test your chlorine level (or bromine, if you go back to that) before you get in to soak, then if it's zero or near zero (< 0.5 ppm), do not go into the tub without adding some sanitizer first and then wait for a few minutes (depending on CYA level -- if CYA level is high, then wait 10 minutes or more), and retest to make sure the sanitizer is still there. Most people just do this initially and then know their "routine" and what their tub needs to maintain a sanitizer residual.

Richard

[soakme]

For your skin doctor prescribed bactran will speed the disappearance of the spots. You might try neosporin if you can't get to the doctor.

For the tub, you may want to raise the water level above normal, super chlorinate and leave the tub running overnight. Might want to throw the bathing suits you were wearing in as well. Then would be a good time to just dump the water and start over again.

You said you switched back to chlorine. I have heard that you cannot switch from bromine to chlorine without draining the tub (but chlorine to bromine is okay). Others may want to chime in on this.

[chem geek]

You said you switched back to chlorine. I have heard that you cannot switch from bromine to chlorine without draining the tub (but chlorine to bromine is okay). Others may want to chime in on this.

This is true -- that's a good catch.

Gary, if you "switched" to using chlorine without draining and refilling the tub, then you really didn't switch. In water filled with bromine and bromide, the chlorine will just act in a similar way to MPS (non-chlorine shock) and will just reactivate the bromine. The tub will not be directly sanitized by chlorine. To truly switch to chlorine, you have to drain and refill to remove all the bromine/bromide.

Richard

[gary3029]

Hi

Yes I did empty, clean and refill the pool. I don't have an issue with maintaining the poole everyday with chlorine. I plan to switch to the bleach method becaue I cannot change the water frequently because I am on a water meter due to rising CYA levels. I assume I don't use dichlor along side the bleach unless I need to raise the CYA.

What do I shock with if I am using bleach?

I do have a question which is confusing me. I have a pool which I use dichlor. Will the CYA just keep rising or is reduced by sunlight?

Rash as nearly gone now and I have got back into the tub, but I am having shorter soaks and showing afterwards. It is actually easier to keep chlorine levels up because if I have to add any the result is instant unlike with bromine. Only time will tell

[chem geek]

You are correct that you don't need to use Dichlor again once you have added enough to get to around 20 ppm CYA in the spa; thereafter you use bleach until your next refill, then start over with about a week of Dichlor usage before switching to bleach again. However, remember that pH rise might be an issue so be sure to test that and let us know how its going. If the pH rises, then you can use dry acid (sodium bisulfate) to lower it. Test the pH before you add the chlorine -- it will rise after you add the chlorine and then will drop some as it gets used up.

If you consistently maintain chlorine levels, you may not need to shock, but if you do or want to you just use more bleach to do so (or for your pool, chlorinating liquid may be more convenient to carry). In the spa with 20 ppm CYA or so, shocking to about 10 ppm FC is usually sufficient, but not normally necessary. Essentially, by using enough chlorine on a daily basis, you are continually shocking the water in terms of breaking down (oxidizing) organics.

The CYA does not breakdown in sunlight. It only goes away via dilution (and sometimes over the winter from soil bacteria breaking it down into ammonia if you let the pool go). If you are using Dichlor in your pool, then the CYA level is probably through the roof. Are you using any sort of supplemental algaecide in your pool, such as PolyQuat 60 or a phosphate remover or copper metal ions? If not, then you're lucky to not get algae. In your pool, you will want more than 20 ppm CYA, but probably 30-50 ppm is the appropriate range unless you are losing lots of chlorine due to sunlight at these levels. You should rarely need to shock the pool if you are maintaining the chlorine level and the shock level would be about 40% of the CYA level, but usually only if you are fighting algae (say, from forgetting to add chlorine).

For both your pool and your spa you should get a good test kit, the Taylor K-2006 you can get at a good online price here or the TF100 kit from tftestkits.com here with the latter having 36% more volume of reagents so comparably priced "per test".

Are you adding chlorine every day or two to your pool? With Dichlor, it dissolves quickly so unless your pool is covered you may find it uses up chlorine such that you need to add it more frequently. If the CYA is very high, then the chlorine may last longer, but won't be effective enough to keep away algae unless you use an algaecide or are lucky (e.g. have very low phosphate levels). If you start using chlorinating liquid or unscented bleach for you pool, you may want to automate its addition by using The Liquidator which is talked about in this thread.

Richard

[gary3029]

Thanks chem geek for your valued assistance things are starting to look clearer.

I think I have it sorted with the hottub and I switch to bleach this weekend and then watch the PH.

With regards to the pool. it is 11,000 litres liner exercise pool. unless in use it has a heat cover + a debris cover becaue I have a alot of trees around. So the pool is rarely exposed to a lot of sunshine unless in use. I do add a algaecid as recommended. So we come back to this CYA build up in the pool if I am using dichlor. Is there anything else I can use that won't involve all this CYA build up seeing that my pool does not see much sunlight unless in use. This rash has been a wake up call to the fact that daily checks means daily checks so maintenence will never be an issue again!!

Many thanks

[chem geek]

The risk of having the bacteria Pseudomonas aeruginosa grow uncontrollably in your pool is much lower than in your spa since this bacteria really likes the higher temperatures. It is certainly found in pools, but it may take more normal chlorine levels to keep it from growing as there isn't a single reported case of itch/rash from pools properly managed with chlorine on multiple pool forums and there are a lot more users than at this hot tub forum.

Since your chlorine usage is low in your pool, you may not be building up CYA that fast, though it doesn't take much. Your 11,000 liters is about 2900 gallons so a very small pool so you could have enough splash-out and backwashing to keep the CYA somewhat diluted. What kind of filter do you have and how frequently do you backwash, if you do? Even so, using Dichlor in a pool is not the normal thing to do. Much more typical is using Trichlor in a floating feeder, but then you have to watch the pH and add pH Up periodically. For every 10 ppm FC that is added, Dichlor also adds 9 ppm to CYA while Trichlor adds 6 ppm to CYA. Either way, Dichlor or Trichlor, you must use an algaecide to prevent algae growth due to the higher CYA level unless you were to keep up the Free Chlorine (FC) level proportionately.

You can save money by using chlorinating liquid or unscented bleach in the pool. The general rule in a manually chlorinated pool is that you must maintain an FC level that is at least 7.5% of the CYA level at all times (this rule works to prevent algae up to a phosphate level of around 3000 ppb which is very high). A decent target to shoot for is an FC that is 10% of the CYA level. So you would treat your pool in a similar way as to your spa except you can have the CYA level go a bit higher -- 30 ppm should be about right if you mostly keep your pool covered. Then, you would just maintain 3 ppm FC in the pool. In my pool that is covered most of the time, the chlorine usage is 0.5 ppm FC per day when not in use, but you may find a slightly higher usage in your pool since it's smaller, though I'm not sure. I need to add chlorine about twice a week, especially when it is in use and consumes more like 1 ppm FC every day when the pool is used most every day.

Even if you switch to using chlorinating liquid or bleach for your pool, the use of PolyQuat 60 algaecide can be insurance to prevent algae growth in case you forget to add chlorine. That's up to you -- the algaecide is not necessary, but will prevent things from turning if the chlorine gets too low.

So, you can probably go either way -- Dichlor or Trichlor with algaecide vs. chlorinating liquid or unscented bleach (with CYA already in the water). With a small pool volume, it's much easier to manage the CYA level, especially if you have a filter that is regularly backwashed weekly (however, I suspect you have a cartridge filter).

By the way, for your spa, you might consider looking into a Nature2 system. That way, if you forget to dose with chlorine, you still have a much lower chance of getting hot tub itch compared to not having anything in the water at all. It's basically like having insurance. Nature2 isn't cheap, but it will help protect your water from uncontrolled bacteria growth though by itself isn't fast enough to kill such bacteria quickly to prevent person-to-person transmission. You don't "need" Nature2 if you always maintain sufficient chlorine levels, but you've seen how it doesn't take very long in missing a dose before bacteria can grow to large enough numbers to cause problems.

Richard

[gary3029]

Richard

The pool I have is a sand filter type, here is link to the type of pool I have. http://www.h2ofun.co.uk/exercise-pools.asp Instructions state I should backwash when the pressure gauge increase by 0.5. I assume from what you say more regular backwashing/topping up needs to occur?

Will it be ok to use bleach with a vinyl pool as I would like to standard my chemicals for both pool and tub.

Regards

Gary

[chem geek]

Gary,

I think you just need to get the good test kit and test for CYA every couple of months to see how its going, assuming you continue to use stabilized chlorine (Trichlor or Dichlor). If it's rising and you don't want to use a supplemental algaecide, then yes you need to dilute the water to prevent the CYA from climbing. If you use an algaecide, then the CYA can get higher without causing a problem with algae (up to a point).

If you instead switch to using bleach, then just test the CYA once now to see where you are at. If the CYA is higher than 50 ppm, then you should do more backwashing and/or partial drain/refill to lower the CYA level. Once it is where you want it, you can then just check after a couple of months or so and see if it is dropping. You won't need to backwash more frequently than you are doing now if you use bleach as your source of chlorine, because it won't increase the CYA level. Keep the Free Chlorine (FC) level at around 10% of the CYA level and you'll be preventing algae (don't ever let it get below 7.5% of the CYA level).

When adding any concentrated chemical to the water (except thick algaecides that explicitly say to spread around the entire pool), you should do so slowly over a return flow with the pump running, preferably in the deep end. For extra safety, you can brush the side and bottom of the pool after you've added the bleach. This will ensure that none settles since concentrated chlorine is denser than water, though when mixed it will stay mixed. There are many, many pool users using bleach in their vinyl pools with no problem. Problems occur when adding chemicals quickly so that they settle in concentrated form or cause the local water to have too much chemical too quickly. When adding Muriatic Acid, it is particularly important to add it very slowly as it is VERY concentrated and also very damaging to vinyl -- most vinyl damage is due to acid addition, but adding chlorine quickly and not mixing it is also not good.

Richard

[gary3029]

Thought I would give an update.

The rash has now gone and my daughter and myself have stopped itching. The other half now thinks I have gone over the top with cleaning and testing the pool, but I am not taking any more chances, I check the spa twice a day now. Surprising how a illness focuses the mind. Have switched to bleach in the hottub and the pool. In the UK it would appear that all bleach come in bottles marked 'less than 5% bleach' The poole is working a treat and PH and TA levels are spot on.

The hottub with the bleach is working great, but the TA is off the scale. The PH is between 6.8 and 7.6 , but still has a tendercey to drop below 7.2. I have tried to reduce the TA but of course the PH crashes, so I then run the bubbles to get it back up, but the TA then increases. My TA is at 180-240 ppm which is very high....what causes this?

The other problem which UK readers may be able to help is I keep hearing about this Taylor test kit, but I have been unable to find one in the UK. Any suggestions on an alternative kit.

As we are on a water meter I have to be careful about wasting water. I maybe well of the ball park here but it is an idea I have. Most evenings I water the garden and must use a fair amount. I thought what if I half empty my spa into water butts every month and refill with fresh water, this should keep the spa running nicely. The water in the butts should quickly lose its chlorine and be safe to use on the garden? I suppose there are many reasons whyI should not do this?

Regards

Gary

[chem geek]

Gary,

That's great that your rash is now gone -- let's hope it stays away. For the bleach, try and make sure it's unscented and has no other additives such as thickeners. You want the plainest bleach you can find, but at reasonable strength. For bleach that doesn't explicitly list an exact concentration (i.e. < 5%), you'll need to measure the resulting Free Chlorine (FC) and adjust accordingly, but if you can find some bleach that is more precise about its concentration, that would be better. In fact, since you have a pool as well as a spa, call up your local pool stores, hardware stores, big box stores, and see if any carry chlorinating liquid aka unstabilized chlorine (sodium hypochlorite). It's stronger than bleach and is usually 10% or 12.5% and will be much less to carry for your pool and can be used in your spa as well (at lower quantities than for the bleach). For example this link is to a company that sells sodium hypochlorite unstabilized chlorine in the U.K. though at £1.1/liter, it's pretty pricey. It's better to find a local source and ideally one that will reuse the bottles (that's what I do with my local pool store).

Keep in mind that if you switch to using bleach or chlorinating liquid for your pool, that this is much more maintenance as you'll have to add it every day or two unless you have a pool cover that keeps the sunlight (UV rays) out of the water in which case you could add the chlorine around twice a week. There's no free lunch here -- the Trichlor tabs/pucks are more convenient but add to CYA. There are automated dosing systems for bleach or chlorinating liquid as shown here and talked about in this thread but I don't think you can get this in the U.K. (maybe someone else makes something like it).

As for the hot tub, the pH should rise when you aerate, but the TA shouldn't climb so I don't know what's causing that in your case nor why your TA is so high. Something is very strange if the pH still has a tendency to drop, especially with the TA being so high. If you are now using bleach, after having used Dichlor for a bit to get some CYA in the water, then the pH will have a tendency to rise, not drop. Either there is some unusual source of lowering the pH yet keeping the TA up or your test kit has a problem. Test your fill water, though that would only explain what would happen when you change your water.

As for using spa water for your plants, just dump the water a day after you've added chlorine and the level should be low so should not be a problem for the plants -- they get watered by tap water that is often chlorinated. The CYA biodegrades (the soil bacteria break it down into ammonia). You should probably just try this out on some plants you don't care as much about to see how it goes, but I don't anticipate any problems.

As for getting a Taylor K-2006 kit, the Taylor website gives the following contact for international sales:

For all pool/spa orders except Canadian, contact HornerXpress Worldwide in Fort Lauderdale, Florida:

954-938-5355 (voice)

954-938-5244 (fax)

[email protected]

LaMotte makes a drop-based kit 7001-NJ/PRO250-NJ though the chlorine test appears to be DPD instead of the preferable FAS-DPD found in the Taylor kit. The LaMotte distributors in the U.K. may be found at this link. Hopefully, someone in the U.K. knows how to get a test kit with the FAS-DPD chlorine test, though it's not terrible if you have to use a kit with DPD instead.

Richard

[gary3029]

Richard

Many many thanks for your wisdom, you have resolved many of my problems and made what appears a difficult job a lot more pleasurable.

THANKYOU

[Hap]

I agree with what was expressed above about needing even more diligence using chlorine than bromine. Also, if you use Dichlor as your sole source of chlorine, then to minimize the risk of getting hot tub itch you will need to change the water more frequently since for every 10 ppm Free Chlorine (FC) added by Dichlor, it also adds 6 ppm to Cyanuric Acid (CYA). The buildup of CYA will make the chlorine less effective as a disinfectant (unless you increased the FC level proportionately which is not practical).

If you don't want to change the water after a month or so, then there is another alternative. After a week of Dichlor usage to build up some CYA, the use of unscented bleach (Clorox Regular or off-brand Ultra) will add chlorine without CYA, but will make pH control harder usually requiring acid addition. If your tub has an ozonator or other significant source of aeration, this would require more acid addition when using bleach. "

Chem geek or any other veteran,

I have a 200 gallon hot tub(Marquis 315) with an ozonator and I use spa frog minerals(blue container), I just switched to using Spa Essentials Dichlor in after each soak which I do twice a day. I have just switched from Bromine, do you recommend using bleach maybe 2 onces after each use? Then testing. The Vermont method that I read about seems to indicate that I should be ok for 4 months and then need to change the water. But your posts suggest that the CYA will get too high and a switch to 6% simple bleach is in order? I really appreciate all the info.

Hap

I am not a chemist should I still get the TF200 test kit? I have been using test strips and they seem fine.

[chem geek]

The TF100 and the Taylor K-2006 test kits are easy to use. You just count drops for most tests until there is a color change or color disappears. Of course, it's faster to use test strips, but most are not as accurate for some of the tests. For daily checking, you probably don't need a lot of accuracy, but every once in a while you'll want to know what's going on accurately and that's when the better test is very helpful.

Most people on the Vermont method, which is Dichlor-only after each soak with enough to have a small residual the next day, have no problems. Using bleach is more work for some who try it, especially those with an ozonator such as yourself, since the tendency of the pH to rise is very strong in that situation. I'm not going to give you a recommendation. Just be aware of the downsides to using bleach after initial Dichlor (for the first week) in terms of the pH rise. Most users who couldn't stand it had ozonators; most that are OK with the method don't have ozonators.

I think that with your Spa Frog minerals you'll be in better shape regarding avoiding hot tub itch as that will hopefully help. I haven't noticed any reports of hot tub itch coming from those using metal ion systems so it seems to be reasonable insurance. So you are probably fine using Dichlor-only (i.e. the Vermont method).

Richard

[anewby]

The TF100 and the Taylor K-2006 test kits are easy to use. You just count drops for most tests until there is a color change or color disappears. Of course, it's faster to use test strips, but most are not as accurate for some of the tests. For daily checking, you probably don't need a lot of accuracy, but every once in a while you'll want to know what's going on accurately and that's when the better test is very helpful.

Most people on the Vermont method, which is Dichlor-only after each soak with enough to have a small residual the next day, have no problems. Using bleach is more work for some who try it, especially those with an ozonator such as yourself, since the tendency of the pH to rise is very strong in that situation. I'm not going to give you a recommendation. Just be aware of the downsides to using bleach after initial Dichlor (for the first week) in terms of the pH rise. Most users who couldn't stand it had ozonators; most that are OK with the method don't have ozonators.

I think that with your Spa Frog minerals you'll be in better shape regarding avoiding hot tub itch as that will hopefully help. I haven't noticed any reports of hot tub itch coming from those using metal ion systems so it seems to be reasonable insurance. So you are probably fine using Dichlor-only (i.e. the Vermont method).

Richard

BLEACH????? in the tub? Are we talking about the same stuff I put in the whites??

Are there any types of mineral or enzymatic additives that can help to break down all the chemicals that we have to use to keep the tubs clean in the first place? It seems like there should be something that helps to cover up or calm the chemicals.

[cplarsen]

Yes, we're talking good old Clorox bleach. 6% chlorine.

The chlorine you buy down at the dealer has been stabilized and granulated for ease of handling, and is a much higher concentration, but it's about the same stuff chemically.

[Hap]

Thanks Richard I will let you know how I do. You have been very helpful!!!!

Hap