Hot Tub Forum

Original => Hot Tub Forum => Topic started by: fishnaked on January 03, 2015, 01:33:24 pm

Title: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 03, 2015, 01:33:24 pm
I have a 5x3 wood fired cedar tub. No jets. No pump or filter. No chemicals. I've been using 35% hydrogen peroxide as the sanitizer. 1 cup weekly is what I started out with. I could only go 40 days max before the water got really slimy at which point I'd drain, clean the tub, and refill.

I tried enzymes. They failed miserably, unfortunately.

I'm currently trying something a bit new: Dumping in 1/2 cup peroxide after each use. After 20+ days, this seems to be working better. But it's not cheap...and I'm not sure how much longer than 40 days I can go between cleanings.

What would be wrong with simply dumping some salt in the tub? Seems not much if anything would grow in a saline solution. If this is a possibility, does anyone know how much salt I might start out with? Has anyone tried this?

I'm fully aware of the standard chemicals...and that they are "safe", cheap, effective, and all that. I could use them but I wish not to for a variety of reasons. So please refrain from recommending them to me. I have extensively searched the web for other alternatives. Everything seems to look like hood-wink marketing or require pumps to circulate (ozone & ionization for instance).
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Rotten1965 on January 03, 2015, 02:20:31 pm
Change the water after each use. 35% Hydrogen Peroxide is NOT a sanitizer it's an Oxidizer. If your going to use it try medical grade which is 3% or by the Baqua Spa oxidizer which is 8% Hydrogen Peroxide which would be safer to use. Salt needs special equipment to turn the molecules into active oxygen which then sanitizes your water. Salt by itself will only soften your water.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Dr. Spa™ Ret. on January 03, 2015, 02:22:11 pm
ummmmmmmmmm, you do know that the ocean has all various kinds of algae and bacteria growing in it don't you? The great salt lakes of Utah also have all kinds of things growing in them.

Now, if you intend to electrify the water (in the correct manner), converting the salt into chlorine...well that's another story.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 03, 2015, 03:26:35 pm
Change the water after each use. 35% Hydrogen Peroxide is NOT a sanitizer it's an Oxidizer. If your going to use it try medical grade which is 3% or by the Baqua Spa oxidizer which is 8% Hydrogen Peroxide which would be safer to use. Salt needs special equipment to turn the molecules into active oxygen which then sanitizes your water. Salt by itself will only soften your water.

Not a sanitizer? I have two close friends (one a fish geneticist, the other a chemist) who speak of using it as a sanitizer in their fish labs. Did I misinterpret their use of it?
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 03, 2015, 03:37:57 pm
ummmmmmmmmm, you do know that the ocean has all various kinds of algae and bacteria growing in it don't you? The great salt lakes of Utah also have all kinds of things growing in them.


Hey Andrew,

Ha......yes, I asked for that one, didn't I!!  :-[ I caught that as soon as I posted. Don't ask me why I didn't edit. Perhaps I wanted to see how people would respond......

At any rate, what would you guys recommend then? I contacted two companies selling enzymes. One said they would not work without a pump to circulate. The other seemed confident enough that his would work that he sent me a free sample. Didn't work. Perhaps if I had circulation?

I live in the desert where the water table is continually dropping (humans are using water faster than ol' mother can replace it.) So, I don't see that draining the tub every time I use it is a wise option for me.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: TwinCitiesHotSpring on January 03, 2015, 03:48:48 pm
ummmmmmmmmm, you do know that the ocean has all various kinds of algae and bacteria growing in it don't you? The great salt lakes of Utah also have all kinds of things growing in them.


Hey Andrew,

Ha......yes, I asked for that one, didn't I!!  :-[ I caught that as soon as I posted. Don't ask me why I didn't edit. Perhaps I wanted to see how people would respond......

At any rate, what would you guys recommend then? I contacted two companies selling enzymes. One said they would not work without a pump to circulate. The other seemed confident enough that his would work that he sent me a free sample. Didn't work. Perhaps if I had circulation?

I live in the desert where the water table is continually dropping (humans are using water faster than ol' mother can replace it.) So, I don't see that draining the tub every time I use it is a wise option for me.


biguanide (Baqua Spa), Chlorine, Bromine, and Nature2 I believe are the ONLY products that have been tested as safe and effective as a sanitizer by the EPA...anything else you find online will mostly likely not have any ingredients listed so therefore your relying on their "marketing" and "testimonials" as truth and most you'll find recommend using chlorine or shock with anyway
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Quickbeam on January 03, 2015, 03:55:19 pm
I use 29% hydrogen peroxide in my Jacuzzi hot tub and it works fine, although my tub does have a UV bulb and a circulation pump. Not sure why your hydrogen peroxide is so expensive? If you are using food grade hydrogen peroxide I think it is quite a bit more expensive and there is no need to use this. Also, are you buying from a health food store? I’ve found they are quite a bit more expensive. See if you can buy from a chemical manufacturer. So you have a reference point, early last spring I purchased a 5 gallon pail of 29% hydrogen peroxide (not food grade) for $50. I should also add that I live in B.C., Canada (Vancouver area).
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 03, 2015, 04:47:09 pm
I use 29% hydrogen peroxide in my Jacuzzi hot tub and it works fine, although my tub does have a UV bulb and a circulation pump. Not sure why your hydrogen peroxide is so expensive? If you are using food grade hydrogen peroxide I think it is quite a bit more expensive and there is no need to use this. Also, are you buying from a health food store? I’ve found they are quite a bit more expensive. See if you can buy from a chemical manufacturer. So you have a reference point, early last spring I purchased a 5 gallon pail of 29% hydrogen peroxide (not food grade) for $50. I should also add that I live in B.C., Canada (Vancouver area).

I've been buying my peroxide here: http://www.purehealthdiscounts.com/h2o2.htm It is food grade. I'm paying nearly double what you pay for more than twice the peroxide: $78 ($92 Canadian) for 2 gallons.  I can get non-food grade locally for a bit less....but nothing close to what you are paying, if I remember correctly.

I've wondered too if my tub being wood makes it more difficult to sanitize.

A friend of mine tried peroxide in his conventional tub and couldn't get it to work either. He has the standard pump/jets/filter but no UV bulb or other sanitizing method.

Have you tried relying solely on your UV bulb?

Also, how often to you drain and clean your tub?

Thanks.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Quickbeam on January 03, 2015, 05:05:05 pm
Our hydrogen peroxide works great, and I wouldn't want to try anything else. I love the feel of it and our skin feels almost moisturized after a soak. Have not tried to rely on just the UV bulb and quite honestly don't intend to. This is our first hot tub and we've had it for less than one year, but so far I've been draining and refilling approx. every 3 months.
Sounds to me like you are paying way too much for your hydrogen peroxide. I have a friend who uses hydrogen peroxide in her tub, and she gets hers from a health food store. She uses 29% food grade and is paying about $80 per gallon. I am getting mine from a chemical manufacturer, and as I mentioned earlier I am paying $50 for 5 gallons of 29% non food grade. I don't know how much it would cost me for food grade, but again, I see no need to use it. See if you can find a chemical manufacturer that you can buy from. I'm guessing it would be a lot cheaper for you.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Quickbeam on January 03, 2015, 06:20:45 pm
Fishnaked,

I sent you a private message.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: chem geek on January 04, 2015, 12:06:01 am
Baquacil Oxidizer is 27% hydrogen peroxide and can be obtained here (http://www.nationaldiscountpoolsupplies.com/baqshoccasof.html), here (http://www.swimmingpool-discounters.com/products-page/pool-chemicals/baquacil1/baquacil-oxidizer-shock), and here (http://buckstovepoolandspa.com/shop/baquacil-oxidizer-shock/) for as low as $17 per gallon.  There is no reason for you to get the food-grade 35% you have been getting at that much more expensive price.

This post (http://www.whatsthebest-hottub.com/forum/index.php/topic,18360.msg187737.html#msg187737) explains the downsides to hydrogen peroxide.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 04, 2015, 11:10:51 am
ummmmmmmmmm, you do know that the ocean has all various kinds of algae and bacteria growing in it don't you? The great salt lakes of Utah also have all kinds of things growing in them.





biguanide (Baqua Spa), Chlorine, Bromine, and Nature2 I believe are the ONLY products that have been tested as safe and effective as a sanitizer by the EPA...anything else you find online will mostly likely not have any ingredients listed so therefore your relying on their "marketing" and "testimonials" as truth and most you'll find recommend using chlorine or shock with anyway

You make a very good point about relying on "marketing" and "testimonials" as truth. If only everyone's moral compass was pointing in the same direction...

On the other hand, something deemed "safe" by the EPA doesn't exactly mean much either when one is familiar with EPA's archaic chemical regulatory process run through the TSCA. Means even less when you read the reports on this process put out by the US Government Accountability Office. The GAO has been reporting on it basically since its inception in 1978. Unchanged since. And I see congress has just severely cut EPAs already underfunded budget. Reason: EPA costs businesses money. Economy over the nations health. Sad! But I digress. That's for another thread....
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 04, 2015, 11:12:04 am
Baquacil Oxidizer is 27% hydrogen peroxide and can be obtained here (http://www.nationaldiscountpoolsupplies.com/baqshoccasof.html), here (http://www.swimmingpool-discounters.com/products-page/pool-chemicals/baquacil1/baquacil-oxidizer-shock), and here (http://buckstovepoolandspa.com/shop/baquacil-oxidizer-shock/) for as low as $17 per gallon.  There is no reason for you to get the food-grade 35% you have been getting at that much more expensive price.

This post (http://www.whatsthebest-hottub.com/forum/index.php/topic,18360.msg187737.html#msg187737) explains the downsides to hydrogen peroxide.

Thanks for the info.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Chas on January 09, 2015, 07:26:16 pm
Here is another option, just for your kind consideration:

Add chlorine as you exit the tub. Small amounts, tablespoon of Dichlor. You should have a sanitized, chlorine-free tub the next evening. Or if you added slightly too much Dichlor, you might have a barely readable level of chlorine. But that low level is not really detectable by your nose, nor will it bother sensitive skin. You will hardly know it's even there.

A second option to play around with: ozone systems which have an air pump. They are small, not real expensive, and as they create ozone they pump it via a little air compressor (actually most use the type of air pump found on aquariums). You drop an air stone on the end of a little vinyl tube to the bottom of your tub, and the ozone helps you use less sanitizers.

JED engineering makes one - Robert's Hot Tub sells it -
JED 203-Description-
The JED 203 is designed for water purification in residential and commercial hot tubs, small pools, fountains, cisterns and water tanks up to 5000 gallons. The JED 203 is supplied in a plastic rainproof enclosure that can be wall mounted outdoors. The JED 203 has its own air compressor which can pump ozone into a pool, tub or tank up to 24 hours a day independently of water circulation. The JED 203 is typically installed in conjunction with an over the side kit or thru-hull fitting.
-Specifications-
Dimensions: 9 1/2" x 8 1/2" x 4 1/2"
Input Voltage: 120 VAC, 60 Hz
Operating Current: 0.42 Amperes
Ozone Output: 0.1Grams per Hour
Power Consumption: 50 Watts
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 14, 2015, 10:38:55 pm
Here is another option, just for your kind consideration:

Add chlorine as you exit the tub. Small amounts, tablespoon of Dichlor. You should have a sanitized, chlorine-free tub the next evening. Or if you added slightly too much Dichlor, you might have a barely readable level of chlorine. But that low level is not really detectable by your nose, nor will it bother sensitive skin. You will hardly know it's even there.

A second option to play around with: ozone systems which have an air pump. They are small, not real expensive, and as they create ozone they pump it via a little air compressor (actually most use the type of air pump found on aquariums). You drop an air stone on the end of a little vinyl tube to the bottom of your tub, and the ozone helps you use less sanitizers.

JED engineering makes one - Robert's Hot Tub sells it -
JED 203-Description-
The JED 203 is designed for water purification in residential and commercial hot tubs, small pools, fountains, cisterns and water tanks up to 5000 gallons. The JED 203 is supplied in a plastic rainproof enclosure that can be wall mounted outdoors. The JED 203 has its own air compressor which can pump ozone into a pool, tub or tank up to 24 hours a day independently of water circulation. The JED 203 is typically installed in conjunction with an over the side kit or thru-hull fitting.
-Specifications-
Dimensions: 9 1/2" x 8 1/2" x 4 1/2"
Input Voltage: 120 VAC, 60 Hz
Operating Current: 0.42 Amperes
Ozone Output: 0.1Grams per Hour
Power Consumption: 50 Watts


Thanks, Chas! I had looked into ozone a while back...and, based on what I had read, ruled it out. Can't remember what it was though. Not overly effective....not totally safe.....I don't recall.

What are your thoughts?

Also, I looked at the model you recommended. Not real clear on what all I'd need though. Does the tub water need to be circulating for it to work?
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Dr. Spa™ Ret. on January 14, 2015, 11:55:07 pm
Ozone wont work, and will quickly deteriorate the wood.

Ozone, while a very powerful oxidizer, is only so, when it's ABSORBED into the water. In order for it to be absorbed into the water it has to have a long contact time with the water, and the water has to be pressurized. Ideally the contact time is 25+ seconds, and the water would be pressurized to at least two atmospheres. In your situation, the contact time would be about 1 second, and the water not pressurized at all. The ozone would bubble to the surface of the water, and being heavier than air would accumulate in VERY high concentrations, and deteriorate the wood above the water line. I saw a wooden hot tub, 3 years old, with this setup, and the wood above the water line had lost 1/2+" of thickness.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 15, 2015, 07:39:21 pm
Ozone wont work, and will quickly deteriorate the wood.

Ozone, while a very powerful oxidizer, is only so, when it's ABSORBED into the water. In order for it to be absorbed into the water it has to have a long contact time with the water, and the water has to be pressurized. Ideally the contact time is 25+ seconds, and the water would be pressurized to at least two atmospheres. In your situation, the contact time would be about 1 second, and the water not pressurized at all. The ozone would bubble to the surface of the water, and being heavier than air would accumulate in VERY high concentrations, and deteriorate the wood above the water line. I saw a wooden hot tub, 3 years old, with this setup, and the wood above the water line had lost 1/2+" of thickness.

Thanks. That's good info to have! The "contact time" was one of the issues I now remember reading about too.

How about UV light? I believe it's expensive and requires that the water be circulated (ie, I'd have to buy a pump = even more $) to be effective. Any other thoughts on that?

Seems there are a lot of inquiries on the Net from folks who don't want to use the standard chemicals but I see few solid solutions. Surely there's something that would actually work. Maybe my expectations are too high. I must say though that dumping ~1/2 cup of 35% peroxide in my tub after each soak works considerably better that the cup/wk I was doing prior. Still though, it's a far cry from what some people are claiming as I'm still seeing some moss 30 days in...and I'm concerned that the peroxide might damage the powder coating on my Snorkel stove.

The Ahhnatural tea bag-like thing looks some what intriguing but it calculates out to be $25/month...or perhaps as little as $16 if one can squeeze 18 months from it like it is claimed some do. What's in the thing though!!??.

EDIT: Just to be clear, I do not expect to keep water in my tub 1 year before changing. I'd be happy to get 4 months between changes. Heck, 3 months wouldn't even be bad.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: chem geek on January 16, 2015, 11:49:46 pm
If you are talking about moss on the wood, then a UV system won't help at all because it only kills what circulates through it.  You need a disinfectant in the bulk water.  You've already been told how you can use chlorine in the spa in a way that you would not notice the chlorine (i.e. dose after a soak such that you start your next soak with hardly any chlorine).

Moss can be killed effectively by copper ions, just as algae is prevented as well.  So a copper/silver/zinc system would work and you could use non-chlorine shock (potassium monopersulfate, MPS) to oxidize the bather waste.  The combination of silver ions and MPS is also an EPA-approved disinfectant (technically only in the Nature2 system since the EPA approves products, not chemicals).  I don't know, however, if there are any problems with using metal ions in a wood spa.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: Dr. Spa™ Ret. on January 17, 2015, 11:12:14 am
No problem with metal ions in a wood spa...however, he has no pump, filter or circulation system of any kind.
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 17, 2015, 01:48:47 pm
Moss can be killed effectively by copper ions, just as algae is prevented as well.  So a copper/silver/zinc system would work and you could use non-chlorine shock (potassium monopersulfate, MPS) to oxidize the bather waste.  The combination of silver ions and MPS is also an EPA-approved disinfectant (technically only in the Nature2 system since the EPA approves products, not chemicals).  I don't know, however, if there are any problems with using metal ions in a wood spa.

Thanks. Couple questions:

What is MPS? What about the peroxide I am using for a shock?

Re the EPA, who approves chemicals then?
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: fishnaked on January 17, 2015, 01:58:04 pm
No problem with metal ions in a wood spa...however, he has no pump, filter or circulation system of any kind.

Thanks. Does that mean the metal ions would not work, or not work as well as they could, without the pump and filter?
Title: Re: Using plain ol' salt in wood tub as sanitizer. Why not?
Post by: chem geek on January 17, 2015, 06:03:37 pm
The metal ions would work as well as anything else you'd add to the tub.  Basically, ANY chemical you add to the tub would need to get mixed in the water somehow.  Once mixed, it should stay mixed.  The metal ions are mostly just dosed after you do a water change since they mostly last.

MPS is non-chlorine shock (potassium monopersulfate).  It oxidizes bather waste and would be added after each soak, but you'd need to stir the water to mix it.

With no filter and circulation, your spa will build up dead skin cells and other organic material since oxidizer products do not completely get rid of them.  The only way to clean out your spa effectively of such items will be with water replacement.