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I think he was screwing with chem geek. The instructions for N2/MPS specifically say add chlorine.
aha, that's interesting.It is striking that Zodiac doesn't mention that in the manual. For me as a nitwit that isn't clear at all from the manual. In fact, if you read the manual carefully (like i do), then it is very clear that you don't need to monitor the MPS level between soaks. Only before and after you enter the tub. Does Zodiac expect that every owner uses his/her tub every 1 or 2 days? Isn't that a very dangerous approach? And surprising for a manufacture from a country where you can sue a restaurant for serving too hot coffee or where they warn you in the microwave-manual that you shouldn't put your dog in it (that's the way we in Europe look to the US with off course some exaggeration).In practice this means that in my case i have to put in some MPS every day, because the level of MPS gets down in 1 or 2 days also if i don't use the tub (maybe because of clearray?)I think i better use chlorine-tablets in a floater during holidays which the neighbours can add once or twice a week.Is it okay to put the temperature to the minumum (80 degrees F.) during holidays? Or shut off the electricity completely?
We don't have a hot tub yet, but hope to get one in the not to distant future. We have friends who do have a tub, and they use hydrogen peroxide as a sanitizer in their tub. They have been using it for some time now, with no ill effects. We have been in their tub and your skin feels silky smooth after a soak. I have talked to a number of hot tub salespeople and so far have not had anyone who has said using hydrogen peroxide will void the warranty. They have said they don't encourage it, but they also tell me the warranty will still be good. I was looking for somewhere to get the hydrogen peroxide and found a chemical supplier that is close to me. They have nothing to do with hot tubs, they are just a supplier of all kinds of different chemicals. When I called them and told them what I was planning on doing, they said they have a lot of people they sell hydrogen peroxide to for hot tubs and they would be happy to put me in touch with one of their salespeople to guide me in how much to use, etc. I haven't followed up yet, but I will when we get a hot tub.Again, I can't profess to know a lot about either hot tubs or sanitizers, but we have a friend who uses it and swears by it and I know others use it and claim to be happy. This is what we will be trying when we get a tub.
Another potential alternative for you is an SWG (Salt water chlorine generator), if allowed by your manufactuerers warranty, which will generate chlorine in your tub by passing electricity through salt water. It sounds like an ideal choice for your situation, however due to the corrosive nature of salt water many tub manufactuers say their use will void the tubs warranty. Those that allow SWG's may do so only for the models that they produce.
Since you are only using the spa weekly, you can add MPS and chlorine after your soak and the chlorine should be gone by your next soak while the MPS should still be there (assuming you add enough of both).The rough rule-of-thumb with no ozonator is that every person-hour of soaking in a hot (104ºF) spa needs 3-1/2 teaspoons of Dichlor or 5 fluid ounces of 6% bleach (or 3-1/2 fluid ounces of 8.25% bleach) or 7 teaspoons of non-chlorine shock (43% MPS) to oxidize the bather waste.And yes, having the water be cooler should slow down the rate of oxidizer loss. It's roughly a doubling of chemical reaction rate for every 13ºF degrees though this depends on the specific reactions so is a rough average for what is typically seen.
Quote from: Quickbeam on February 24, 2014, 03:05:53 pmWe don't have a hot tub yet, but hope to get one in the not to distant future. We have friends who do have a tub, and they use hydrogen peroxide as a sanitizer in their tub. They have been using it for some time now, with no ill effects. We have been in their tub and your skin feels silky smooth after a soak. I have talked to a number of hot tub salespeople and so far have not had anyone who has said using hydrogen peroxide will void the warranty. They have said they don't encourage it, but they also tell me the warranty will still be good. I was looking for somewhere to get the hydrogen peroxide and found a chemical supplier that is close to me. They have nothing to do with hot tubs, they are just a supplier of all kinds of different chemicals. When I called them and told them what I was planning on doing, they said they have a lot of people they sell hydrogen peroxide to for hot tubs and they would be happy to put me in touch with one of their salespeople to guide me in how much to use, etc. I haven't followed up yet, but I will when we get a hot tub.Again, I can't profess to know a lot about either hot tubs or sanitizers, but we have a friend who uses it and swears by it and I know others use it and claim to be happy. This is what we will be trying when we get a tub.To have hydrogen peroxide be effective as a disinfectant, you need it at around 50 ppm concentration and at that level some people find it to be irritating. It is not approved as a disinfectant by the EPA for the U.S., but Australia approves it for use in spas. If you want an inexpensive source of hydrogen peroxide, you can get 27% concentration from Baquacil Oxidizer or Aqua Silk Chlorine Free Oxidizer, but that may be more than you need. You can also get 3% concentration from your local drug store. 50 ppm in 350 gallons would be 223 ml (just under a cup) of 27% while it would be 9-1/3 cups of 3% (it takes more than 9 times as much of the 3% because the density is somewhat lower compared to 27%).This paper indicates that hydrogen peroxide required higher concentrations of 1000 ppm to kill Legionella pneumophila quickly (99% in 30 minutes) but that 100 ppm killed the bacteria over 24 hours.
But, i think that during a longer holiday a chlorine-tablet floater will be a good idea.
i use it almost daily, but i was putting things in perspective. Trying to understand what the consequences are. The amounts you mention are very different from Zodiac. I have a 375gallon tub and i soak with 2 people for an hour. According to the manual i should put in 1,5 tablespoon (4,5 teaspoon). Your advise is 14 teaspoons? Do i understand this correct?
The only chlorine tablets are Trichlor (well, I'm ignoring Cal-Hypo, but they're a mess and not appropriate) and these usually aren't used in a spa because they dissolve too quickly in hot water and you have to be careful about not overdosing which can drive the pH down, exhaust the TA, and damage metal as a result. If you use a proper floater with a solid top and narrow tube that closes off a lot, then it is OK to use, though it will still be very acidic coming out of the floater and if there is no circulation and the floater parks itself near something, then the acidity could be harsh on nearby spa surfaces (especially metal).You can certainly drain the tub when you leave but unless you fully remove the water from all lines you'll likely need to decontaminate upon your return and that's a tub full of water to fill, add Ahh-Some, then after running circulation and jets you then drain and fill again. Another alternative is to keep it full of water, but lower the temperature a lot and perhaps use AquaFinesse to inhibit biofilm formation. I'd still decontaminate when you return, but at least that's just one drain/refill instead of two.Basically, not having a disinfectant in the water at all times makes getting bacterial biofilms risky. If the water was clean with no organics from usage, then the risk is far lower, but think of a spa's initial greases and subsequently your body waste (sweat, urine, dead skin cells) as delicious food for bacteria.
The Nature2 Spa Mineral Sanitizer Owner's Manual from Zodiac Pool Systems says before each use to test the water's MPS level and if low then add 1 tablespoon of MPS per 250 gallons. It also says to add that amount after each use. This amount is roughly equivalent to 4 ppm FC in oxidizing power and would roughly handle 35 person-minutes of bather load in 350 gallons, but they do not recognize that the dosing after a soak is independent of spa size and that it should be proportional to bather load.So yes, their recommendation is significantly underdosing given your relatively high bather load. However, the actual amount you should dose is whatever it takes so that you don't get too low or to zero in between your soaks. So adjust up your dosing so that you measure enough MPS for the start of your next soak. If your spa temperature during the hour of soaking is less than 104ºF, and I suspect that it is since you normally can't soak that long at that high a temperature, then the rule-of-thumb of 7 teaspoons of MPS per person-hour would be lower at the lower temperature. Also, this rule-of-thumb assumes no ozonator. With an ozonator, the ozone should handle a lot of the bather load, usually around half.