DaveP

@ItchyandFrustrated I'm not a spa expert like Waterbear and others on here, but this is my experience, it may help you: We got our hot tub 2 years ago, newbies. Followed the instructions from the spa dealer, fine for a few weeks, but often had cloudy water, dealer was hopeless, said it was fine etc. Then I started itching, skin rash (just me, not my wife or kids), I would go in once and then spend 4 or 5 days getting rid of the rash/itching. Finally came across this site/post and switched to the Dichlor/Bleach method after purging etc, which fixed the water, but I still had the skin problem! By a process of elimination I found that I had a reaction to CYA. So I completely removed Dichlor and anything that may have CYA from my process and then had zero problems after that. My skin is fine and the water is clear. So my process now is that I do a water change every 6 months, balance the water to get the PH and Alkalinity right (using the method on this forum), then I add concentrated bleach with no additives as santiser. I'm in the UK and I just order Sodium Hypochlorite (bleach) 15% (sold as patio cleaner) from Amazon. Every time we come out of the tub I add the right amount of bleach and then every now and again (2-3 days) I add a bit more (50ml) if no-one is using the tub. For my tub (Jacuzzi J-375 - 445 gals / 1685 litres) I find that I need to add 70ml of 15% bleach per person-hour of bathing. If I ever get it wrong and it goes a bit cloudy I dump 2-300ml of bleach in there and it clears it up overnight. The tub has a UV lamp in the system which cuts down any excess chlorine. I don't know if this is the best way, but it's the only way I've found to stop my terrible skin irritation which would have meant selling the hot tub! And the water is crystal clear 99% of the time. I don't use any other additives of any sort. Hope this helps.

@dashmer Thanks. This is a useful comparison. I've got cloudy water again after having kids in etc over the weekend, I clearly didn't add enough bleach again. I've been cleaning the filters and I'll do another decontamination at next water change. With this help, I'll get on top of it soon I'm sure. Thanks again.

@RDspaguy Thanks for your help with this, much appreciated!

@RDspaguy Thanks for that explanation! I never understood that about UV, so that's really useful. I don't think I'm adding enough chlorine after use from what you have said. I will increase it. I'm trying to get a more accurate figure for the daily fc demand, but it sounds like the UV is going to make that difficult or even irrelevant. For example, in the last 24 hrs it has used up 6ppm of fc, taking it down to 0.5ppm. I just added what should be about 7ppm fc, but am I just wasting my time trying to chase a residual at all if the UV is going to burn it off? Should I just add bleach a few minutes before people go in, then after according to bather load? Thanks for your help.

Thanks for the replies guys, just got back to this. @RDspaguy I don't have Ozone, but I do have UV - I didn't realise it has that effect, thanks, I'll take that into account. Does that mean the UV is actually doing more harm than good? @dashmerI'm using 15% bleach (sold as pool chlorine) as the max domestic bleach strength is 4.3% in the UK and they all have additives. I'm using about 20ml (0.7 fl oz) bleach per bather hour now - higher than I was doing, but I wasn't keeping on top of it before. Still trying to get the right dose though. The tub is about 1700l (425 us gal). I have purged it with Ahhsome a couple of times in the past 6 months. I'm still finding it hard work - I can't miss a day, otherwise it drops to zero fc and goes cloudy. Having said that, it gets used 3-4 times a week, so I guess that's just the price to pay using Chlorine?

Hi I switched to Chlorine from Bromine a few weeks ago as I was getting a bad skin reaction (I'm fine now, with Chlorine). I'm using Nitro's method and it's all been going well, but I'm having an issue with keeping on top of it. I'm testing and adding bleach pretty much every day (which is a pain), but sometimes the kids go in and don't add bleach back afterwards, or I might miss a day for some reason. I'm trying to keep it at about 3-4ppm, but the swings are quite dramatic, so I tend to keep the dose higher. It seems to very easily use up the Chlorine and it's turned cloudy a couple of times last week, before clearing up after I put a high dose of bleach and add MPS. I made sure the TA, PH etc are all balanced nicely. PH is at 7.4 and has stayed consistent, TA is about 100. I'm not sure of my Chlorine demand recently, but to start with it was really high (about 90%) before I added MPS, then it stabilised to about 25% per day. So my question is - am I doing something wrong, or is a Chlorine tub sensitive to swings like this (I never had the same problem with Bromine)? Any tips for a Newb Cl user? Thanks.

@Cassiemoreira An update, in case it helps anyone: I ditched the Bromine, switched to Chlorine about 4 weeks ago and I've had no reaction since. So for me, it was the Bromine that caused the skin irritation - or to be more specific, I was using Bromine granules which consisted of Sodium Bromide and Dichlor (which I hadn't realised before) - Jacuzzi branded, but fairly common mix I think after checking other brands. Now I use the Nitro method, so I kicked off with Dichlor and switched to bleach, with MPS dosing weekly or after a big load. That's working fine, but requires more work that the Bromine did.

@Cassiemoreira Thanks for your reply, I will try the bathtub with the bromine chemicals and hope I get the maths right! Then maybe switch to Chlorine if it causes the reaction. Thanks!

Hi guys, First post on the forum, been reading avidly for a few months. Great forum, learned loads. I have the exact same problem that @Cassiemoreiraand others here describe. I'm in the UK and got a Jacuzzi J-375 hot tub last summer. I was fine in it for a few months, then started to get itchy raised skin on arms, legs, torso, kept me awake etc. lasts about 4-5 days. Since then I've tried everything I've found here, multiple Ahhsome flushes (got plenty of gunk out), not using MPS to shock, switched to proper test kit instead of strips, etc. I'm running Bromine, no ozone or anything like that. Also started using Silk balance. I also tried using Aveno to moisturise afterwards and always shower immediately. Last weeked was my last test, first dip after water change - nothing but some Bromine granules to get sanitiser to about 6ppm, and I had the reaction again after about 12 hours. No-one else in the family is affected at all. Should I try a switch to Chlorine? I'm out of ideas and confused as to why it would be fine for months, then suddenly start and not go away. Any ideas? @Cassiemoreira did you ever get a solution? Thanks