Localised itching on back - from the jets?

[HottubTim]

I wonder if anyone has experienced this, my water is balanced, other hottub users don't have an itching problem, I don't have an itching problem other than on my central back area which is suspiciously in the area where the jets provide the most massage effect (and is the most difficult area to scratch ).

The tub is a new Hotspring relay with the salt system, been running it for a month as a test before I Aahsome purge, drain and refill in the next few days, I maintain chlorine above 3ppm, I shock after use with additional Sodium Hypochlorate 14% and use the dichlor to bleach method (CYA is at 50 from first fill having gone a tad too far with the dichlor).

I can measure fCl, tCl and CCl using my Pool Lab 2.0 and notice that CCl's range from 0.8 to 2.0 after a soak, so I then shock up to 10ppm chlorine which brings it down, but I haven't managed to get it below 0.8 CCl so far. I haven't used any other oxidisers other than bleach, should I try something to get the CCl to zero?

The itching is localised which makes me think it's something to do with the water jets, it could be just a sensitive back that I have or it could be the water pressure pitting my back with nasties or chlorine, the tub will be squeaky clean after the next drain, I had a break of about 16 months from hottubing from the last hottub before this new Relay and didn't have an issue before (the tub before was not water balanced as well as this one is), any thoughts or experiences from you guys ?

 

[Bperry]

I wonder if anyone has experienced this, my water is balanced, other hottub users don't have an itching problem, I don't have an itching problem other than on my central back area which is suspiciously in the area where the jets provide the most massage effect (and is the most difficult area to scratch ).

The tub is a new Hotspring relay with the salt system, been running it for a month as a test before I Aahsome purge, drain and refill in the next few days, I maintain chlorine above 3ppm, I shock after use with additional Sodium Hypochlorate 14% and use the dichlor to bleach method (CYA is at 50 from first fill having gone a tad too far with the dichlor).

I can measure fCl, tCl and CCl using my Pool Lab 2.0 and notice that CCl's range from 0.8 to 2.0 after a soak, so I then shock up to 10ppm chlorine which brings it down, but I haven't managed to get it below 0.8 CCl so far. I haven't used any other oxidisers other than bleach, should I try something to get the CCl to zero?

The itching is localised which makes me think it's something to do with the water jets, it could be just a sensitive back that I have or it could be the water pressure pitting my back with nasties or chlorine, the tub will be squeaky clean after the next drain, I had a break of about 16 months from hottubing from the last hottub before this new Relay and didn't have an issue before (the tub before was not water balanced as well as this one is), any thoughts or experiences from you guys ?

The FC getting down to 0.8ppm while you are in the tub would be something to look at. But that’s only if we believe the poollab results can be trusted. Note that We don’t really trust them.

 

[Newdude]

CYA is at 50

With a hot tub you should be dosing to 10+ (@50 CYA) and falling back into target range.

One of *you* in 500 gallons is the same as 68 people in my pool, and those people aren't being stewed into people soup.

 

[HottubTim]

The FC getting down to 0.8ppm while you are in the tub would be something to look at. But that’s only if we believe the poollab results can be trusted. Note that We don’t really trust them.

Certainly the FC whilst in the tub is something to look at, but it wouldn't really explain why the itching is localised to the back area.

It's the Combine Chlorine that can range from 0.8 to 2. Why is the Pool Lab not to be trusted, it's a lab grade photometer? In the UK the Taylor test kits are available, however reagent resupply is thin on the ground for the Taylor whereas the reagant tablets for the Pool Lab are bountiful. Results from the Pool Lab have been consistent in the 40+ tests I've performed so far.

 

[HottubTim]

View attachment 639448


With a hot tub you should be dosing to 10+ (@50 CYA) and falling back into target range.

One of *you* in 500 gallons is the same as 68 people in my pool, and those people aren't being stewed into people soup.

Yes, I am dosing to 10ppm after a soak and I've added some during long soaks also and then I'll top up again the following day, maybe letting it fall to 3ppm at 50CYA is not so good, CYA will be corrected at next fill.

 

[Bperry]

Certainly the FC whilst in the tub is something to look at, but it wouldn't really explain why the itching is localised to the back area.

It's the Combine Chlorine that can range from 0.8 to 2. Why is the Pool Lab not to be trusted, it's a lab grade photometer? In the UK the Taylor test kits are available, however reagent resupply is thin on the ground for the Taylor whereas the reagant tablets for the Pool Lab are bountiful. Results from the Pool Lab have been consistent in the 40+ tests I've performed so far.

If the CC is really 2.0 that would be an even bigger pointer to the issue.

I don’t know all the details of why the electronic devices aren’t reliable but it’s been the case with people coming here wondering why there’s a problem even though their testing with “XYZ electronic device” says everything is fine. Something about the photometers becoming more unreliable especially when the CYA increases over 30ppm is one part of it, but not the only issue. There’s just never been a consumer grade device that has proven to be reliable and accurate, or their error tolerance is so large, it’s comical. Does the PL provide error tolerance on its test values? You might be surprised at how much variance is considered “normal”.

 

[AUSpool]

Before you clean and refill it try soaking in a different spot away from the jets.

 

[Newdude]

Yes, I am dosing to 10ppm after a soak

That doesn't help *for* the soak. You're being exposed to what's causing the rash during the soak, not after.

CYA will be corrected at next fill.

Purge the tub with ahhsome at that time.

 

[wireform]

Yes, I am dosing to 10ppm after a soak and I've added some during long soaks also and then I'll top up again the following day, maybe letting it fall to 3ppm at 50CYA is not so good, CYA will be corrected at next fill.

CYA will come down on it's own between the heat and the time duration. The bigger issue is where the CYA is really at.

 

[AUSpool]

If the CC is really 2.0 that would be an even bigger pointer to the issue.

I don’t know all the details of why the electronic devices aren’t reliable but it’s been the case with people coming here wondering why there’s a problem even though their testing with “XYZ electronic device” says everything is fine. Something about the photometers becoming more unreliable especially when the CYA increases over 30ppm is one part of it, but not the only issue. There’s just never been a consumer grade device that has proven to be reliable and accurate, or their error tolerance is so large, it’s comical. Does the PL provide error tolerance on its test values? You might be surprised at how much variance is considered “normal”.

I’ve not heard of interference from CyA before. Interesting . CyA interference for ORP is well known but I’m not sure that mechanism applies to photometer. Photometers add an extra assessment step, two if you count the algorithms. As the DPD reagents ages it gives a false positive but old reagents is a problem for all kits. The sample volume to tablet is quite small and the tablets don’t always completely dissolve before assessment. I sound very negative but I do own a PoolLab and have played with it a bit. I got erratic results from CyA testing but know someone else with one that was seeing consistent results when comparing the PL to the disappearing dot on the same samples.

But it’s easy for me, I was just tinkering and stayed with my K2006 kit. But in the UK I believe drop test kits are hard to find. If hottubtim is careful with it he could probably expect to be within the +/-10% mark. But there is always an element of doubt.

 

[HottubTim]

If the CC is really 2.0 that would be an even bigger pointer to the issue.

I don’t know all the details of why the electronic devices aren’t reliable but it’s been the case with people coming here wondering why there’s a problem even though their testing with “XYZ electronic device” says everything is fine. Something about the photometers becoming more unreliable especially when the CYA increases over 30ppm is one part of it, but not the only issue. There’s just never been a consumer grade device that has proven to be reliable and accurate, or their error tolerance is so large, it’s comical. Does the PL provide error tolerance on its test values? You might be surprised at how much variance is considered “normal”.

I shall increase the ppm to try and consistently bring the CCl level down.

Yes the manual states +/- 10% tolerance and 0.1 tolerance for pH

 

[HottubTim]

Before you clean and refill it try soaking in a different spot away from the jets.

Started doing that

 

[HottubTim]

That doesn't help *for* the soak. You're being exposed to what's causing the rash during the soak, not after.

Purge the tub with ahhsome at that time.

Good point, will ensure there's a higher level of ppm before the soak

 

[AUSpool]

And then trying to find out what’s actually causing the reaction is like trying to figure out how long a piece of string is. Does the tub just need a good clean? Is the CyA too low and the FC too reactive?Why just you? And why in a spot you can’t reach?

 

[HottubTim]

CYA will come down on it's own between the heat and the time duration. The bigger issue is where the CYA is really at.

If tolerance +/- 10% is to be beleived and the test value is to be beleived then levels are hovering around 50. On next fill I will calculate ppm CYA from the dichlor and see what it tests at, bit more of a scientific approach.

 

[Newdude]

And why in a spot you can’t reach?

I'm thinking it's a sensitive area from rarely being exposed to anything.

 

[HottubTim]

And then trying to find out what’s actually causing the reaction is like trying to figure out how long a piece of string is. Does the tub just need a good clean? Is the CyA too low and the FC too reactive?Why just you? And why in a spot you can’t reach?

All good questions, the tub was new but haven't had a chance to purge yet, there could be something lurking it could be my CL dosing regime, CYA looks to be a bit on the high side therefore CL levels could be low for the CYA - I will increase ppm.

 

[HottubTim]

I'm thinking it's a sensitive area from rarely being exposed to anything.

Centre of the back and surrounding area, hardly gets sunlight never mind anything else, but the hottub jets are directed at that area, it could be a sensitive area which is then blasted with water that contains some nasties that hasn't yet been killed/oxidised by the chlorine possibly because CYA is too high for the PPM at the time. I don't have a rash or anything else, just itching.

 

[AUSpool]

Started doing that

The problem is that you’ll have to wait till the reaction or rash has cleared up first.

I know your pain. I got a reaction to a hot tub in a holiday rental. But I’ve been in that tub before on a previous stay without a reaction. And when we moved to another rental, in another resort - no reaction. I didn’t have the lecture of self testing. We were the first occupants that season so maybe the CyA was low and the FC was harsh. Maybe it had dent been cleaned properly after being dormant over the summer and needed a good clean. In truth I’ll never know. And the reaction I had was probably completely different to what you’re experiencing.

 

[HottubTim]

I’ve not heard of interference from CyA before. Interesting . CyA interference for ORP is well known but I’m not sure that mechanism applies to photometer. Photometers add an extra assessment step, two if you count the algorithms. As the DPD reagents ages it gives a false positive but old reagents is a problem for all kits. The sample volume to tablet is quite small and the tablets don’t always completely dissolve before assessment. I sound very negative but I do own a PoolLab and have played with it a bit. I got erratic results from CyA testing but know someone else with one that was seeing consistent results when comparing the PL to the disappearing dot on the same samples.

But it’s easy for me, I was just tinkering and stayed with my K2006 kit. But in the UK I believe drop test kits are hard to find. If hottubtim is careful with it he could probably expect to be within the +/-10% mark. But there is always an element of doubt.

I've just tested CYA and it came out at 52 on the Pool Lab 2.0, so still consistent with previous tests, Chlorine, TA and pH are also consistent with previous tests so it doesn't look like the tester is messing up even though it might still be out 10% either way. Reagent tablets are recent purchase with long shelf life left on them, my testing processes and equipment is consistent, I crush and ensure that the tablets have dissolved, it could be consistently wrong or consistently correct, either way at least it will be consistent .

There are parameter settings on this device, mostly aimed at testing professionals so the machine parameters can be adjusted if things start getting inconsistent. They can also supply reference cuvettes for checking readings, at this point in time I don't have reason to believe that the tester is showing fault.

The 10% variance that Pool Lab quote is based on equipment and user error.