Tinkers

Thanks for the input!! Much appreciated! We live in Missouri, and we were just questioning if it is due to a larger difference between outside temperature and hot tub water temp. It was upper 40's the night of the 14th when she had no problems but had dropped back down into the 20's last night. We keep our temp low (100) because we like to sit in there for longer periods of time than most people. Your rash sounds the same as hers as well. Thanks again for the reply!

Hot tub specs: 1 1/2 year old Clarity Spas Balance 7, 390 gallons of water measured with a flow/gallon meter at end of hose along with a carbon pre-filter attached. Currently converted to Salt water using a ContolOmatic Smarter Spa SWG. We have been using this system off and on for the last year with Morton Professional Pool salt in between testing other sanitizing systems. We use a SWG in our 4500 gallon above ground pool and the wife has NO issues with rashes. Water Chemistry measured with a Taylor K2006 test kit. Water Temp: 100 pH: usually runs between 7.8 & 8ppm with the SWG system with little to no drift keeping the Alk at 60 ppm Alk: 60ppm. If I raise the Alk then the pH wants to drift higher at a quicker rate. CH: 100 Salinity: 1600ppm CYA: 0 Cl: 2ppm, we turn on the SWG boost button either while in tub or right after we get out. (Have tested this trying both ways) There is NO bacteria in hot tub water! I have changed the water at least 10 times in the last year and a half since getting the tub brand new and have been using Ahhsome Spa purge each water change. There is NO scum or scuzz of any color in the foam. Foam shows bright white after each purge and I purge the tub for at least 30-60 minutes along with raising the chlorine level to 20ppm before draining, refilling and running a thorough rinse cycle, draining again, wiping interior of tub and cover with vinegar water before the final fill. There is no way there is any type of bacteria (Pseudomonas aeruginosa). Which, btw, does not present or look the same as the rash that she develops in various places on her body. We have tried EVERY sanitizer system...liquid sodium hypochlorite (HTH brand liquid chlorine 10%), Bromine, Nature 2 with low level sodium hypo, the frog system both chlorine AND Bromine, standard floater with bromine tabs and sodium bromide bank with no luck. I have done EVERY step to the letter of what has been listed in this forum as far as the different methods of utilizing bromine and chlorine systems. I have tried using the ozonator and unplugging it with different refills with NO difference as to her developing a rash. I use standard baking soda and muriatic acid to maintain the pH and Alk. My tub is as simple as I can get it as far as what's in the water...Arm & Hammer baking soda, muriatic acid, and salt (this refill) which is the same as what we use in our pool. On the occasions that I have shocked the tub it has been with liquid sodium hypochlorite waiting for the chlorine levels to drop back down to 2-3 ppm before getting into the tub. Filter gets cleaned and rotated out every 2 weeks. We ALWAYS shower before getting into tub and when it's just the two of us we do not wear bathing suits. We do not use MPS non chlorine shock as we KNOW that she is allergic/sensitive to that. No one else (which has been maybe 4 people over the course of the last 1 1/2 years) that has been in our tub has had any problems with rash or skin issues. I'm in it WAY more than her and have NEVER had or have a rash. On this last purge and refill (2/13/2024) I intentionally did nothing to the water after refilling as far as Alk and pH (I kept it as it is straight out of the tap because she never breaks out from showering in it this way). Those readings were pH 10+, Alk 40ppm which is what our city water is straight out of the tap which was confirmed with the Taylor test kit and what is listed on our city water department website. I let the SWG get the Cl up to 2ppm with out adding any liquid sodium hypo to jump start it and the ozonator turned off. Basically the ONLY thing I added to the water after the fill was 9 cups of salt which I know from experience brings the salinity level to 1600ppm and this was confirmed by the Taylor salinity test. From the time of re-fill to us getting in the tub for the first time on this fill was roughly 36 hours. We sat in the tub for an hour the following evening on 2/14. The water felt silky smooth and Wife was perfectly fine the next morning with NO rash anywhere! I left the tub as it was, only checking on the Alk, pH and CL which were the exact same the next time we got into the tub for an hour on 2/16 (last night) pH 10+, Alk 40ppm and Cl 2ppm. This morning she has several spots of rash that came up after being in the tub last night. Yes she has tried showering after being in the hot tub and that has NEVER made a difference as to whether or not she breaks out. I/we are at a total loss at this point. It seems she is fine or has very minimal rash the first 1 to 3 times of use after a purge and fill no matter what sanitizer system we have tried. After the first few days to weeks after a purge/refill she starts to develop the rash and it progressively gets worse after each use the further past the fill date we get. I have tried keeping the sanitizer at various levels in what is considered the "RECOMMENDED" levels for each system we have tried to no avail. We use a SWG system in our above ground 4500 gallon pool every summer and she has been fine with that up until last summer when half way thru the season I added pure boric acid to both the pool and hot tub for water clarity and pH drift. She started developing an even worse rash and it took some detective work to figure out that was the culprit. So we quit using boric acid in both the pool and hot tub. MY QUESTIONS ARE: Could something (chemical) from what the inside of the cover or piping is made of be "leaching" into the water over time? Is there something else that I can use to flush the tub to make sure it has no chemical residues left over in the pipes that could possibly be causing her skin issues? If it is a case of her not being able to soak in hot water (aquagenic urticaria, which presents differently than the rash she is experiencing) then wouldn't that occur from the very first time being in the tub and not several soaks (days or weeks) into a fresh fill? What does muriatic acid turn into after added to the water to bring the pH down? What does the baking soda turn into after added to the water for bringing the Alk up?

Thank you for the reply. The tub is extremely clean. I have done numerous (6) Ahhsome purges and is just 1 year old. No gunk of any color or kind is coming out of the tub. I started putting boric acid in the tub last October and that is when the "poison ivy" looking rash started to appear. I put boric acid in our pool for the first time 1 month after opening it for the season this summer. She was staying out of the tub and getting into the pool only and the rash was not clearing up. Drained, purged, emptied, filled and rinsed, emptied again then refilled tub. No boric acid this time. Went with the 3 step bromine set up. We do not use MPS because we know she is sensitive to that from a previous use of it last fall. Shock only with sodium hypochlorite. She got in it 3 nights ago after the drain and refil. Chlorine was showing 2 ppm and bromine 4-5 ppm. Alk 50 ppm, ph 7.6, and she broke out again but it was different in that it looked like a sunburn but was better in 24 hours. Got into tub last night (alk 50, ph 7.6, Cl .5, Br not registering) for an hour and she was fine this morning with no rash. She is sensitive and allergic to EVERYTHING which makes it tough. Were you meaning to say Bromine is a known SENSITIZER and chlorine is not?

So I have read until I am cross eyed and can't find a straight answer here or anywhere on the web. Question is: If I decide to use dead sea salt in place of regular pool salt in my tub will I be creating a bromine tub or a chlorine tub since dead sea salt has bromides as well as other minerals in it? I have read about the increased conductivity of dead sea salt and salt water generators. I have a Master Spa Balance 7 which is a 390 gallon tub, and use a Controlomatic Smart Spa SWG. I also use the https://www.masterspapartsonline.com/products/eco-pur-charge-filter.html#:~:text=Next-,X268532 - Master Spa - Eco Pur Charge Filter-PMA-EPR,-Master Spas Copper and Zinc oxide mineral insert in my filter which can't be used in a bromine tub. I use this in order to keep chlorine levels low as possible due to my wife's HIGH sensitivity to chlorine and bromine. We have also learned she can't have boric acid in the tub or pool as well due to skin issues. The tub also has an ozonator. I don't have any issues with water balance or chemistry thanks to the wealth of knowledge that I have gained from reading this forum. I am really interested in trying the dead sea salts from all the benefits I have read online in regard to skin issues. I keep my tub at Alk 50, pH 7.6, CL .5, Salt @ 1600ppm. I have ALWAYS purged my tub with Ahhsome every 4 months at water change time and have nothing growing in it. Thanks in advance to any and all that could shed some light.