Salt vs. Chlorine

[Canadian_567]

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!

[castletonia]

What kind of hot tubs are you looking at?  Salt can be either chlorine based or bromine based.  On a chlorine based system, saltwater tends to have a softer feel, minimal if any chlorine odor and allows for longer water life requiring less frequent water changes.  It's been a long time since I have used a bromine based salt system but from what I remember you still have the longer water life and reduced odor compared to using bromine tabs.  Both systems require user input and will continuously sanitize your water.

I sell a lot chlorine based salt systems with Hot Spring and Caldera.  My competitors which do not have a salt option generally bash salt because they cannot offer it.

Salt, in my opinion, will be less harsh on your skin.  You can also use other products such as Silk Balance, Aqua Finesse, Spa Complete, etc that will supposedly result in softer water.

[Canadian_567]

We've looked at Arctic Spa and Beachcombers.

[bud16415]

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.         

[HotTubLife]

I've had a Hot Springs Envoy with an ACE salt system for about 2.5 years now. I have only just this month found the need to change the salt cell. It seems that 'The Scepter' is a much lower cost replacement (closer to $250, rather than $700+ for the ACE). I can confirm that the 'water feel' with a salt system is quite nice, and the need for full-drain-and-refill is pretty minimal. I've moved to every 6 months from 1 yearly. Water maintenance is really not that big a deal - although I did move to a digital/reagent chemistry system from the terribly unreliable test strips. Especially for Ph levels, the colors were really tough to discern for me. Given how critical the Ph is to keeping components intact, I elected to get more precise. Those with better color vision might not feel the need.

[Spatech_tuo]

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!

I'm guessing the dealer that doesn't have salt offerings is the one who isn't a fan of spas with salt systems. You're going to run into that, what else can you expect them to say? At the same time there is no reason to compare the water you find in a public pool/spa to what you'll be running in your backyard. It will be helpful is the dealer you work with seems to have a good handle on the water care end, some are good at selling but you want real post-sale service in this area though with time you'll pick up on it and many here can help.

[bud16415]

I agree that dealers that do not have a salt offering will point out the negatives and leave out the positives. That is one thing but telling people how devastating the addition of salt will be to their tubs is another. I was point blank told that with salt in a tub to not expect more than a year or two until major systems are eaten up by the salt. If they want to dissuade people from salt systems they should be talking about the number of years you will get from that anode and the cost of replacement. With the unit buried in the tub there is no way to clean off the buildup that kills them. The external units can be soaked in vinegar once a month and are good to go. When they do fail in about 5 years I’m told by someone who runs one the replacement cost is about 100 bucks.

All the options are a trade off between cost of operation and easy of use. As an example with my dichlor/ bleach and 20 lb bag of baking soda and a few jars of other things bought on line or at the grocery store I’m spending between 50-80 dollars a year on tub supplies. I’m needing a new filter now after 5 years not because it’s dirty but because the bands around it and the ends are wearing out. Cleaning it with a jet nozzle and 150 degree water is the key to keeping a filter alive IMO. So factoring in filter costs it might be 100 bucks a year so far. I started off with inline frog bromine and minerals and then switched to @ease inline chlorine that worked great. It was mostly cost that had me move away from those products. Changing those cartridges every 3 weeks was just a waste of money. Now if you could buy cheap bulk @ease chlorine and they had a cartridge that was made to be filled that would be a great option. You are paying for the convenience with many systems, and that is fine if that is what you like. Salt gen systems built in are up there high on the  convenience list IMO.

I do think just from what I read here that many people getting them are under the impression that the tub will take care of itself with one. I assume that’s what they got from the people that sold it.         

[swilly1000]

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.         

Awesome post.

[silversun]

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?

[bud16415]

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?

As I mentioned I have a friend that has been using and loving his aftermarket Saltron Mini. I haven’t been in his tub but we often talked about our tubs at work and he told me he liked the feel of the salt water as well. I had the idea of switching over as I was running bromine with all kinds of issues and I first switched to dichlor and then to dichlor/bleach method. In the back of my mind I kept thinking about salt/chlorine and needed to add a GFCI near the tub if I bought the unit. I got the idea to just try the salt alone to see if we liked the feel of it, and we did. I added the same amount as if I had it hooked up for salt and we have a Caldera Geneva that’s around 350/400 gallons and that came out to be 7 pounds of salt. As I was enjoying it someone here posted that their dealer was suggesting salt also in a non salt gen tub and asked if anyone knew about doing that and if it was ok. By that time I had about 6 months in on the water and it seemed to me to be easier to take care of with the salt in the water. That’s just my opinion and I have no proof but it seemed to make the tub more stable with the ups and downs. As far as I know that person was also going to do it.

My biggest problem wasn’t with adding and testing the tub, but was what to do when we go away for a week or two. My tub came with an inline frog feeder that takes the @ease chlorine cartridges that are good for a month. What I did is I popped the non removable cap off and dumped the contents into another container and when we go away for a week I use ¼ of it if we are gone 2 weeks I use half, 3 or 4 I just put a full one in. right before we leave I shock it and also add a double dose of dichlor and put the canister in. So that solved the going away problem.

It has been so smooth the last year or so with the salt and the dichlor/bleach and shocking with non chlorine shock once in a while and of course keeping the filter clean that even though I still want to add the salt gen I never seem to get around to it.

I always have said if you are in your tub every day you know what is going on for the most part. Maybe once a week I test it and tweak something. That will or should be the same with or without a chlorine generator system. So what it amounts to is the time it takes to add a tablespoon of dichlor or 1/3 cup of bleach after our soak. Maybe 30 seconds at most.

As a side note we were at the county fair and our local hot tub guy was there. He pushes these enzyme drops and I know two people that use them. They tell me you fill your tub and put in 27 drops and you are good for a month next month 27 more drops and so on at the end of one year drain and repeat. It seems crazy to me. I have seen their tubs and they always look perfect they have lots of kids in and out and they swear by these drops. I can’t convince myself that the tub doesn’t need sanitized properly. Anyway I was looking at their new tubs and I get the sales pitch for enzymes again and asked what I do now. I told them I add salt and then use dichlor and bleach and I was told how the salt will eat up my tub nothing flat and the chlorine is destroying my skin.

Bottom line is there is a lot of mystery and black art and misinformation to this hobby.

Now I’m going to go out and soak away my pains in my mild salt water and let that 1ppm of chlorine remove one millionth of an inch of my skin. Knowing what is floating around in the air is likely worse.        

[Sam]

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.

[bud16415]

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.

Will do. I don’t expect any problems as many people are now using salt in very similar tubs (factory units) and many people are using them in tubs with these DIY (aftermarket units). If there were great numbers of failures I would think people would be writing negative on line reviews at the third party seller sites.

The real only difference is that I’m adding the salt just for the sake of having salt in my water. When we sweat it is salt water and when we swim in the ocean it is very salty water. All tubs will dry your skin as the hot water removes natural oils in the skin. My recommendation to people if they really want to get max benefits of a hot tub spa is to shower before and then soak “au naturel” then shower of with just water dry off and then use a moisturizing product. That IMO is the full spa experience. After all a hot tub is not there for productive time it is there to pamper your mind and body like a mini vacation at the end of a long day. 
 

[dw886]

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).

[bud16415]

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).

I agree with you 100%.

As a side note I do something else I rarely hear talked about with my tub. I have hot water available right at my tub from the house hot water system. I use it for filter cleaning mainly and there is about 50 gallons of 140-150 f water available at any given time. if I blend it with cold I can add water at any time without really cooling the tub. I use this water a couple times per month to top off from evaporation and splash out maybe an inch or two. Beyond that in the cold months up north here I will do a partial drain and fill to lengthen water live and get rid of some of the products building up in the water. I have a 2” pool hose and my tub is about 3’ above grade so a siphon is easy to start and I can drain out say 100 gallons in a couple minutes and refill that with hot water in 20-30 minutes. I will then add maybe 1-2 pounds of salt when done. Kind of a situation of the solution to pollution is dilution. My stabilizer stays in check better and overall the water is less wonky after doing this. I really think I could go years with a partial water change solution but I feel it is a good idea to get it empty a couple times a year and clean it really good with vinegar. That just keeps that acrylic with that slippery new feel.
By the way the pool hose connected to 4’ of  PVC pipe makes a great way to suck up stuff from the bottom of the tub, little stones or sand etc.

I just wanted to mention this because you were talking about salt building in a tub over time and it’s not to hard to get rid of 25-30% of it quickly along with other things.

When I add my salt I weigh it out in a large plastic bowl. I set the bowl and salt on the cool down seat under water and just forget about it and let it dissolve slowly into the water.