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We’ve visited two dealers and both are giving drastically different opinions on salt vs. Chlorine. I could really use some opinions of those with the different systems or the help of those who have done lots of research. My son and I have terribly sensitive skin and react to public pools. I realize they crank the chemicals up but that’s where I am starting from. Thanks!
Welcome to the forum. Like you I’m just a consumer of hot tubs and not in sales or service. I have had my tub about 5 years and salt systems were not as prevalent back then in hot tubs but widely accepted in pools. I asked the same questions and got the same variety of answers you have been getting. Before I get into my opinions on salt as a sanitizer medium, know that salt is put in the water to produce chlorine with an electrical device that splits out the NaCl into Na and Cl the Cl being chloride. So in effect you will be soaking in a very similar chlorine tub if you just daily added Dichlor granules to your water. Dichlor and other variations also have other things added that you may find desirable in your water the biggest one is stabilizer. Stabilizer or CYA is put in it mainly for outdoor pools that are not covered and get lots of sunlight. It slows the action of the chlorine so you get a more level usage of the chlorine. Sunlight breaks down the stabilizer so having some in each time you sanitize replaces what is lost. A little stabilizer also helps in a hot tub but with it being covered it builds up over the life of the water and eventually becomes a problem. In the case of a salt generator making chlorine it is not a sudden dose of chlorine once a day it is a constant release of a small amount. Now comparing a motel hot tub / pool to a home hot tub. They normally don’t know what they are doing and error on the side of being overly high. They don’t have people coming in after showering and with fully rinsed swimsuits plus the bather load is many times what you will have at home. So it is not uncommon to have a commercial tub as high as a homeowner might get the tub when shocking it. We don’t know how sensitive your skin is but it is likely a home hot tub wont cause a problem if you maintain it and keep the levels correct. City water has chlorine added to it that we bathe and cook with and it shouldn’t be that much higher in your tub. As to the salt concentration in a salt gen tub. It is nothing like ocean water many, many times lower and is said it is about as salty as a human tear. I was told that salt will ruin my tub nothing flat and will eat it up like road salt and a 1980s car. I’m far from an expert but IMO most all the parts in a hot tub are made from materials that this low salt concentration should be just fine. Many dealers make a large profit on selling chemicals and that has some degree to factor into what you may be told IMO. On the other hand salt doesn’t make a tub automatic and that you just enjoy it and never have to test it or add anything. It is a constant slow adding of chlorine and depending on bather load might not be enough to keep up. If you have it set for say 2 people using the tub once a day for 30 minutes and then you have a party and you have 6 people in it for 2 hours and maybe they didn’t clean their suits as well or had on body lotions etc. you will still then need to add some dichlor to cover the extras or wake up the next morning to cloudy/smelly water. As an example I don’t have a salt gen system and I treat my tub when we get out each evening. So after treating my chlorine level jumps up and it has 20 hours to sanitize the water. It might have been 5PPM after adding the chlorine but the next time I use it is down close to zero or 1PPM. A salt gen tub may be right around 2PPM all the time. you go to a hotel pool or tub it might be 20PPM and you get that strong chlorine smell that shows even at that it is not fully working. IMO salt does add an improved feel to the water and many comment on that feeling and like it. We all have found different methods that work for us, mine is different than most. I do add salt to my water but don’t generate chlorine from it. I use dichlor when I refill my tub and watch the sanitizer level and when it reaches 30-50PPM I switch to regular liquid household bleach Clorox. Along with that I watch the ph and make some tweaks to other things here and there. You need to do those things regardless if you use a salt gen or not. One last thing and something I have been thinking of doing for a year or so. There are aftermarket salt generators made for hot tubs on the market. They don’t get added into the tub at all they hang on the outside and get plugged into a 120v GFCI outlet and you just toss them in and out of the water with use of the tub. So it is possible for under 300 bucks to convert a non salt tub to salt as a DIY project. I have a friend that has used one of these for 5 years now and loves it. Hope some of this answers a few questions for you. I wish I had had someone explain it to me.
Bud - I hadn't considered adding salt to the hot tub without using it to generate chlorine, but I like the idea. How much do you add? And, is it for the benefits you mention in your post or another reason?
I really want to try this. I love that you are doing this experiment and are having good results. If you have any failures or see any signs of corrosion please report back. It's good to hear actual real world results.
I researched this to death before I put in a salt water pool. You'll see opinions both ways. At the end of the day, the amount of salt in a pool or hot tub is about 1/10 what is in ocean water. All hot tubs / pools have some level of sodium in them.If you hear someone claim that they'd never put salt (sodium or NaCL) into their pool or hot tub, ask them what they're using for chlorine. If you read the label on "Dichlor", it's "Sodium Dichloro-s-trianzinetrione". If you read the label on bleach, it's "Sodium Hypochlorite". So whether unknowingly or knowingly, all pools end up with some levels of Salt in them. I've seen pools that were never "salt-water" pools, and when tested, had higher levels of salt than a saltwater pool simply from the compounding effects of sanitizing with a sodium-based sanitizer over the course of multiple years. Now with a hot tub, this is pretty unlikely to happen, as the water is replaced more regularly than in a pool...If you purposely add salt, and then use a salt water chlorine generator (such as the Ace system, Saltron Mini, ChlorMaker, or SmarterSpa), then you know what level of sodium you have in the water, and it's not slowly increasing because the device is splitting the NaCL for chlorine sanitization as Bud describes in his post. If you sanitize with another chlorine based method, then after a fresh fill, you're starting at close to 0 ppm salt, and slowly building it up over time (potentially to a higher level than if you added salt and used a chlorine generator).