Nature 2 And Rash

[restricted]

Pool store worker here, long time lurker, this issue has me stumped and figured bounce it off some brains in the interwebs.

New spa customer with nature 2 stick in filter. Activated correctly with low dose of dichlor.

Adding small amount of oxidizer (monopersulfate) few times weekly as maintenance.

Both husband and wife break out in rashes.

Watertest shows VERY HIGH Total Chlor/Brom levels and everything else in balance including low free chlor. (strips)

With the low free chlor and the high total I was tempted to think that the rash could be caused by chloramines. Also from experiences, sometimes the total strip can light up do to oxidizers which in large amounts surely could irritate skin. No idea which it was or if it was something else.

So, we did what any good store would do, especially with a rash situation, told them to drain, clean and refill. Gave them a new N2 cart and told them to add 1tbsp of dichlor as directed in the instructions.

They brought in another sample today and it appears that the exact same thing is occurring. The pH and Alk were great as was the hardness. The Free Chlor was a 1.5 which is very strange for only 1 tablespoon after 24 hrs. The total Chlor was rocketing up. Obviously told not to get in but this has me perplexed.

Thanks for any thoughts.

[PFC5]

I think MPS actually makes Combined Chlorine (FC-TC=CC) read higher than they are for a few days. Also AFAIK, MPS will not show up as FC, but will add significantly to the total chlorine reading, but with the CYA still near zero since only 1 tbsp of Dichlor was used so far, the chlorine is going to be very strong. You want about 30ppm of CYA (stabilizer) so the chlorine is not too strong even with small amounts used, but not higher than 50ppm or else chlorine will be as efficient. Maybe shocking with more Dichlor to get the CYA levels higher but without the water capacity being stated it would be hard to tell how much.

Since after the rash no one purged the spa or super-chlorinated it, I would think dosing with 10x the Combined Chlorine (Free Chlorine-Total Chlorine = Combined Chlorine) might be a good idea to burn off the CCs. But they would have to wait until FC drops back down to 5-6ppm. I am pretty new with owning a spa, so maybe get an expert to comment on a better course of action.

[chem geek]

PFC5 is correct. MPS will normally register as CC though at high doses soon after addition it can also show up as FC. MPS is a sensitizer for some people so maybe that's the cause of their rash. However, after the drain/refill if they only added Dichlor and got a lot of CC, then that's not good. As FPC5 said, sounds like you may need to decontaminate the spa, perhaps with Spa System Flush and/or superchlorination as their could be biofilms present -- likely actually if they never decontaminated their new spa. Spas are generally wet tested, but the lines are not blown out and dried so the water their as bacteria grow and form biofilms. Also, new spas have a lot of leftover organics from manufacturing.

[waterbear]

Pool store worker here, long time lurker, this issue has me stumped and figured bounce it off some brains in the interwebs.

New spa customer with nature 2 stick in filter. Activated correctly with low dose of dichlor.

Adding small amount of oxidizer (monopersulfate) few times weekly as maintenance.

Both husband and wife break out in rashes.

If you are using N2 with MPS then you need to maintain the MPS level by adding it before AND after each soak. I suspect Pseudomonas from unsanitized water because the MPS level is too low.

BTW, you indicate that you are using strips for testing so I would consider your readings suspect at best. Just because one test shows a high MPS level (that is the "CC" you are seeing) it does not mean that the level has been kept high enough consistently to keep the water sanitized. I suspect you got your water sample right after an addition of MPS.

(and people wonder why I don't care for N2).

[Hillbilly Hot Tub]

I agree, you have to use a lot of MPS with Nature 2. I would also decontaminate the spa as said. You need a better testing system, customers are relying on you for correct info. You also need to follow the recipe exact and make this clear to your customers. Also with Nature 2, if the spa is used daily, they may need a dose of chlorine 2-3 times a week. The weekly dose is for light use (couple of people, weekend users) If they have guests with Nature 2, we always suggest a small dose of chlorine before and after, guests tend to "drag" in addtional germs ect. so I would rather be safe. One of my first questions to customers is how the spa will be used, a lot, by whom, kids/teens ect. and depending on those answeres I may steer them away from Nature 2 with an explanation to why.