Tinkers Posted February 17 Report Share Posted February 17 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? Quote Link to comment Share on other sites More sharing options...
rmcderm313 Posted February 17 Report Share Posted February 17 Hey Tinkers. I have the same issue (me not my wife). I've tried just about everything to help but I've come around to the fact that my skin is sensitive to hot water and it seems to be cumulative. We mostly use our hot tub on Weekends. On Friday I'm fine, on Saturday I start getting itchy and by Sunday I start seeing a rash. I get red bumps and sometimes they get bad enough to weep. My wife has never had any adverse reaction. I have found keeping my PH on the lower side helps a bit. Showering after doesn't seem to have a significant difference. I think my skin is just super sensitive. I'm not sure where you are from a climate standpoint, but in the Winter in the Northeast it's the worst. I think because my skin is dry and compromised to begin with. We don't really use the tub in the Summer so I can't tell if my skin would do better when it's healthier to begin with. I know this probably doesn't help much but your situation isn't unique. -Rob Quote Link to comment Share on other sites More sharing options...
Tinkers Posted February 17 Author Report Share Posted February 17 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! Quote Link to comment Share on other sites More sharing options...
waterbear Posted February 18 Report Share Posted February 18 Some people will experience a rash when exposed to hot water. It is a form of hives or heat rash and if it only affecting your wife is one of the most likely explanations, the other being hot tub itch (which seems more lkely since you said it only starts occiring on "older' spa water. However, a few other things jump out at me.: 6 hours ago, Tinkers said: CYA: 0 Chlorine can be more aggressive with no CYA present, even though it is not a known sensitizer. (Bromine, on the other hand, is.) Try running the CYA at 20-30 ppm and FC at 3 - 5 ppm. If your CC is below .5 ppm you do not need to shock. It is rare that a properly runnign salt water system will need shocking or When do you shock shock to 12-15 ppm with sodium hypochlorite and wait unti the FC is below 10ppm before yon enter the tub. 6 hours ago, Tinkers said: 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. You can go as lot as 40 ppm if ph rise is too fast. Adding 30-50 ppm borate will also help stabilize pH for a longer period of time. I recommend boric acid over borax since ti had a smaller effect on pH and does not require the addition of acid at the same time. Boric acid and borax are used in vaginal supositories, bath salts and bath bombs, btw. and, while the powder is an irrirant because of it's low pH, it is not a known sensitizer. 6 hours ago, Tinkers said: There is NO bacteria in hot tub water! How do you know this? Have you has a bacteriological water analysis done? 7 hours ago, Tinkers said: 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. One word of caution, You MUST do a complete drain and refill (possbily more than one to account for water left in the plumbing) if you want to go back to chlorine after using any form of bromine or you will still have a bromine spa. 7 hours ago, Tinkers said: Could something (chemical) from what the inside of the cover or piping is made of be "leaching" into the water over time? possible but whether it can cause a rash is doubtful or the would be several cases documented. 7 hours ago, Tinkers said: 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? Hot tub flushes are chemicals designed to break up biofilm. Some contain enzymes. Some are detergent based. You can do several drains and refills with plain water after to help flush out the plumbing. 7 hours ago, Tinkers said: 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? Usually. If the rash only starts occurring after the water hah "aged" I would look to bacterial or protozoal causes such as pseudomonas (hot tub itch) , which some people are more sensitive to than others 7 hours ago, Tinkers said: What does muriatic acid turn into after added to the water to bring the pH down? Chloride ions, Muiatic acid is HCL and when it neutralized something akaline it does so by donating the hydrogen ion to the OH ions in the water creating basically water and salt. 7 hours ago, Tinkers said: What does the baking soda turn into after added to the water for bringing the Alk up? When baking soda is dissolved it forms sodium ions and bicarbonate ions, which, depending on pH reach an equilibrium between bicarbonate ions and carbonic acid, which is basically carbon dioxide dissolved in water (seltzer). This post explains it a bit more: https://www.poolspaforum.com/forum/index.php?/topic/28846-lowering-total-alkalinity-howto/ Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.