Hey everybody,
Got me a 6 person hottub, using oxy-spa non-chlorine shock (monopersulfate compound) to shock it weekly in the recommended amount (sometimes a bit more), PH tends to be on the low side so I maintain with 'alkilinity-up'. Filter cleaned weekly (even if we're not using it at the time), but twice now my friend (who must be more susceptible to it) will get hot tub rash. I've even been in the same time and no rash for me. We've tried making sure people shower immediately before/after with antibacterial soap. I've tried shocking it 20 min before using it to prep, and in the spring we will be draining it anyway to give it a thourough scrubdown and refill, but wondering if anyone out there has any advise on any other chemicals (that will cooperate with the non-chlorine shock) or methods that might be helpful. Thanks so much as usual!

You're "assuming" it's a reaction to the chemicals, which it may be, or not. Many people do seem to be allergic/sensitive to MPS, but for your friend it could simply be soaking in hot water causing the problem (rash).. Grovers Disease.

It could also be caused by the low pH, or the pressure of the jets hitting his skin.

It also could be a bacterial infection to a bacteria that you are immune to (not all that uncommon)

It is bacterial, I was just hoping that maybe there were additional chemicals or a different routine I could use to get to the bottom of it. All seems clean... but appearently not entirely. Thanks though!

My apologies, I just reread your post a little more carefully.

What are you using for a sanitizer?? Monopersulfate MPS is an oxidizer that will burn up dead organic debris. MPS is NOT a sanitizer and really won't kill very much. You REALLY need to use chlorine or bromine. Either will work just fine with the MPS as a shock.

Using oxy-spa non-chlorine shock- %100 monopersulfate compound. It was my understanding that mixing with any other type of shock creates weird chemical reactions- gels and such. My father in law uses this kind and never had any problems... even with my 'rash-sensitive friend'. Trying to not use the really harsh stuff, Am I missing some kind of enzyme solution? I realize there are a few schools of thought on the topic,any advice would be helpful. Thanks!

I agree with the Doc, your friend may get his rash other ways than your tub. If you want to experimemnt drain the tub and refill with fresh water, no chemicals, allow to come up to temperature and see if your friend breaks out again. I use bromine with a UV light bult into the unit, no problems.

Well, she's only gotton the rash after using the tub (its happened twice, but not every time we've used it) and was diagnosed by a doctor as foliculitis (aka hot tub rash)complete with perscription to treat the bacteria. So I KNOW that it is from the tub, but aside from the drain/clean I'm doing asap (still cold up here) just wondering if anyone has anu OTHER advise/enzyme/chemical suggestions. Thanks so much

Again;

Monopersulfate MPS is an oxidizer that will burn up dead organic debris. MPS is NOT a sanitizer and really won't kill very much.

MPS will NOT kill the bacteria that causes foliculitis.

First check your chemicals twice a week for now. Then raise you PH with spa up (Regal chemicals has this and it raises both the ph and alk at once.) You didn't say if you are using a scent, if you are stop. I understand that you use the non-chlorine shock(oxidizer), but that only breaks down the hair, body oils, and such. You have to use something else to break down the bacterias. Something like a nature II stick, bromine, or chlorine or such.

Hesitant to go for the harsh stuff, going to try the nature II stick. Thanks to all for all your imput!

Nature II sticks are a great way to samitize your tub, but remember they are actually a mineral pack. Zodiack Nature II wands are made with zink and silver, if you have hard water and have to put metal out in you water the wand might not be as efficiant. I have on customer who has hard water with copper, and he like to use the nature II he has learned to libe with pretty blueish water.