Disclosure: I have absolutely no affiliation, no financial interests, no business nor personal relationships with Spa Marvel. I paid a local in-town pool supply store full price for one bottle of Spa Marvel Water Conditioner, for the purposes of trying to eliminate hot tub itch, not for the purposes of using less sanitizer/chemicals.
Background: Got my first spa in December 2020, and had dry/itchy skin from the get-go. From December through March. I've conducted months of extensive skin reaction testing, using low chlorine, high chlorine, low MPS, high MPS, waiting weeks for MPS to dissipate, waiting 15 minutes after adding each chemical before soaking vs waiting hours after adding each chemical for thorough dispersion/dissipation before soaking, showering immediately after soaks vs not, applying moisturizer immediate after soaks vs not, etc etc.
From all of that, I have determined that MPS caused my "hot tub itch" (in my case, this means extremely itchy/dry/scaly patches of skin - NOT bacterial infection of hair follicles aka folliculitis). It was also a bad idea to super-dose MPS and then jump in after 15-30 minutes of circulation - the MPS (and/or trace amounts of other compounds commonly found in MPS products) seems to have caused chemical burns that weakened some parts of my skin, making those parts to this day more sensitive to everything, including chlorine, hot water, many fabric blends, and maybe even made this skin more susceptible to folliculits bacteria when there was very low chlorine during the above-mentioned testing.
After months of trying everything, and after weeks of cutting out MPS and having partial relief, I decided to give Spa Marvel Water Conditioner a try. The very first time I went in after adding the bottle of Spa Marvel, it completely cured my post-soak skin itch. After the first soak, it thoroughly soothed and rejuvenated my skin, like swimming in moisturizer. I was very impressed and emailed them to let them know.
Note that I had not rinsed or purged the spa after delivery - filled, balanced, sanitized right away, and this was a never-filled floor display model for many months before they sold it to me, so there were definitely biofilm buildups from factory wet-testing many months even before my dealer got it. I also did not have any borates in at this time.
I emailed the Spa Marvel guy (Tim from their website blog), asked lots of questions, and he confirmed that it does not contain any borates. He says it only contains:
* Naturally derived enzymes that come from plant extracts
* Sodium
* Food-grade glycerin
* Distilled water
There are many mixed reviews of Spa Marvel on the Internet, and I believe this is due to several factors:
1) Spa Marvel advertises the ability to use less sanitizer and to allow pH to be higher. From reading Amazon reviews, many people took this to the extreme and did not maintain any sanitizer levels and let their pH get too high, resulting in their hot tub water changing to bad colors and growing funky things. I assume they had biofilm buildups before starting the Spa Marvel regime, and their low sanitizer in a high pH environment was a recipe for rampant bacteria and biofilm growth.
I didn't change my water balancing or sanitization regime after using Spa Marvel - I maintained sanitizer levels as normal, 3-6ppm FC daily and shocking to 10-20ppm weekly. I use the dichlor+10.8% pool chlorine method, and after long soaks (which occur weekly to twice weekly), I raise FC to 10-15ppm. I also had my ozonation+dual filter system running at the default 4 hours per day. With the typical hot tub pH creep without borate use, I knocked pH to 7.2 whenever it rose above 7.8 and kept TA at 50. I also keep a Nature2 spa stick in my filter bay.
2) In the past, Spa Marvel had some batch production issues. The bottle I had was from a super-concentrated batch (I emailed them asking why it was so goopy and why the lid seal seemed defective), so perhaps this super-concentration is why it resolved my skin issues in one soak. Perhaps other batches didn't have enough product to produce this moisturizing/soothing effect.
3) They advertise 3 months of the beneficial effects, but I only got 1-1.5 months out of it before the "soaking in moisturizer" feeling went away. Last week, I did my first water drain, and killed biofilms with Ahhsome. Upon refill, I added 1/3 of the bottle of Spa Marvel, to see if I can get 3 months out of 1 bottle. Using 1/3 of the bottle has significantly lower "swimming in moisturizer" effect than using the full accidentally-super-concentrated bottle that I first had, but still no post-soak itch. I may adjust my regime to add one full bottle per month just for the skin moisturizing effect.
My recommendation if you're itchy after soaks:
1) Completely eliminate the use of MPS (preferably drain all MPS-dosed water, and preferably remove biofilms from plumbing and filters using Ahhsome with hyperchlorination before draining), drain through drain port in order to decontaminate that dead-end pipe.
2) Refill and balance (don't add anything you don't need to, only use what is needed to get CH, TA, pH, FC, CYA in line), superchlorinate after refill and use a new Lysol blue sponge (3M sponges fall apart too easily) to scrub all surfaces with superchlorinated water, including behind seatbacks if you have a Bullfrog
3) Keep pH at 7.4-7.6, and never let FC drop below 3ppm, preferably top to 6ppm FC every day
4) Before first soak, shake well and dump a whole bottle of Spa Marvel Water Conditioner (not their filter cleaner!) in.
If this procedure doesn't alleviate your skin itch, you either got a bad batch of Spa Marvel, or you unfortunately wasted $25-50 on Spa Marvel (not much in grand scheme of hot tub purchase) and need to consult a dermatologist with a list of every single ingredient you put in your spa water, as dermatologists have wide access and knowledge of skin-related research and publications, whereas water chemists are less likely to.
spamarvel.com
