New Sundance Spa - Choosing a Sanitizing Routine

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contentedPilgrim

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Jul 6, 2022
21
Idaho Panhandle
Just bought a new Sundance 980 series Lisbon hot tub which has both an ozonator and UV. I want to use a mineral cartridge plus minimal chlorine with weekly shock. Sundance pushes a Frog@Ease & trichlor cartridge system with MPS/Chlorine combo shock. I won't use their chlorine cartridge system due to waste and cost. I'm looking for the best alternative. I've done a lot of reading on this site and over the years.

I plan to use the Nature2 mineral cartridge as I have used it am very happy with it. As for the chlorine, for the past 16 years, my method has been to add 3ppm of dichlor with water change and never add any more. I have shocked once per week with MPS along with 2 tbs after each use.

Questions: So I know that chlorine quickly dissipates.
  • But what actually happens to it?
  • Does adding MPS reactivate it completely?
  • Or is adding some dichlor regularly required?
My goal is to keep chlorine at 0.5 ppm, Presuming I really should be replenishing the chlorine level,
  • what is the minimum I can get away with - how much and how often?
I understand testing for chlorine using this method might be futile because it dissipates so quickly.
  • Is it worth investing in the new (to me) R-0867 Deox Reagent, so I can test for chlorine when using MPS?
  • My kit is over 3 years old. I figure it's time to replace the whole thing. Is the K-2006 still considered the standard?
Spa usage is just for my wife and I a few times a week. No lotion or oils, etc. Thanks for your input.
 
You need a sanitizer in a hot tub - NEED, or else you are playing a dangerous game. Really.

Minerals do not do anything other than remove money from your bank account (If they make you feel happy that you are using them, then OK)

You have two choices for a sanitizer in a hot tub - Chlorine or Bromine. That is it. No minerals, no MPS, no magic formula, nothing else. Bromine or Chlorine.

Bromine works, but I do not use it, nor do I feel qualified to speak to it's pluses or minuses

MPS is not a sanitizer, it is an oxidizer. It can help to remove the combined chloramines that are in your water after chlorine has done it's sanitizing. However, a good number of people develop a rash from MPS. Look up MPS dermatitis. You know what also burns off combined chloramines? More chlorine.

Sun and heat (aside from organics) consume free chlorine. UV light breaks the hypochlorite ion's bonds turning into Cl gas, and this allows the free chlorine in the water to off gas.

The 3ppm of Dichlor you add at startup is gone in a day

The amount of Chlorine you should have in your water depends on the amount of CYA (stabilizer) you have. Tables are available on this site.

You need to add chlorine every day (just about). Or as was mentioned, use a SWCG which does it automatically
 
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phonedave said:
You need to add chlorine every day (just about). Or as was mentioned, use a SWCG which does it automatically
Click to expand...
+1. And also after every use.... and maybe even during use with multiple users or extended soaks. (With a break to treat and mix, of course).

*cracks knuckles*

OK here goes. :) Your large hot tub holds 500 gallons. Having only 2 bathers in the tub is the same as me having 140 in my 35k gallon pool.

Full stop so that can sink in.

Now let's discuss why 2 users in your hot tub is *worse* than 140 people in my pool. They are hot and sweating and their skin is exfoliating. You aren't enjoying your hot tub, you are making people soup. I won't even go there about the communal bidet that you are enjoying. 100-104 degrees is the perfect temperature for bacteria and swimmer to swimmer transmissions to flourish, unlike my 78 degree pool, which still has concerns of course, but not turbocharged concerns.

You need your tub fully sanitized both during use, and in between uses. Copper is an algae prohibitor, and it does work, but takes a long time to sanitize. Silver can alsi be a disinfectant at the proper levels with long exposure, and you will have neither in your hot tub. If you must use 'minerals', you must use them *on top of* a regimented sanitizing process, which renders them moot when no algae or ickies can flourish due to already being sanitary.
 
Newdude said:
+1. And also after every use.... and maybe even during use with multiple users or extended soaks. (With a break to treat and mix, of course).

*cracks knuckles*

OK here goes. :) Your large hot tub holds 500 gallons. Having only 2 bathers in the tub is the same as me having 140 in my 35k gallon pool.

Full stop so that can sink in.

Now let's discuss why 2 users in your hot tub is *worse* than 140 people in my pool. They are hot and sweating and their skin is exfoliating. You aren't enjoying your hot tub, you are making people soup. I won't even go there about the communal bidet that you are enjoying. 100-104 degrees is the perfect temperature for bacteria and swimmer to swimmer transmissions to flourish, unlike my 78 degree pool, which still has concerns of course, but not turbocharged concerns.

You need your tub fully sanitized both during use, and in between uses. Copper is an algae prohibitor, and it does work, but it does exactly zero sanitizing. Silver can be a disinfectant at the proper levels with long exposure, and you will have neither in your hot tub. If you must use 'minerals', you must use them *on top of* a regimented sanitizing process, which renders them moot when no algae or ickies can flourish due to already being sanitary.
Click to expand...

100% Agree

My specific routine is

I add 2 oz of bleach to my tub almost every day. If we do not use it on a given day I can get away with skipping a day here or there. It will still keep an acceptable level of FC (and since I purge with AhhSome when I do a water change, use Aqua Clarity weekly, and stay on top of filter changes/cleanings, I don't have much in the way of internal nasties).

I also add 2 oz of bleach (even if I have added my normal daily dose) after a soak. Most of the time is just 2 people for 30 min. Occasionally up to 4 for 30 min. Very rarely do we go with enough people or for long enough to warrant a mid-soak dose.

I test FC/CC and test and adjust pH 4-5 times a week or so.
 
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Sorry to hijack the post but what are the advantages of going chlorine route vs bromine. Bromine seems easier and more stable at higher temps and pH changes so why would anyone want to go chlorine route. Just asking since I've always used bromine but might think to switch next purge if chlorine route gives some benefits.
 
Krulligo said:
what are the advantages of going chlorine route vs bromine
Click to expand...
For one, having a plethora of chlorone geeks to help if anything is ever out of whack. Most everyone here choses chlorone because we already all know it.

Way back when I failed spectacularly using bromine in my tub forever shocking up and oxidizing down. (Or thereabouts, i still dont fully grasp the bromine stuffs) Poolmath or similar probably would have helped the yo-yo-ing but it was pre-TFP.

The whole time my pool sat a few feet away chugging along on easy mode with a SWG. I would go either liquid chlorine or SWG if I was to do it again.
 
Krulligo said:
Sorry to hijack the post but what are the advantages of going chlorine route vs bromine. Bromine seems easier and more stable at higher temps and pH changes so why would anyone want to go chlorine route. Just asking since I've always used bromine but might think to switch next purge if chlorine route gives some benefits.
Click to expand...

I know chlorine, and I have chlorine chemicals and equipment.

I looked at bromine, and really didn't see much in the way of benefits from what I would be doing (residential, low usage). If I was looking at a commercial tub, or having heavy bather loads, then I might have been swayed to bromine.
 
phonedave said:
I know chlorine, and I have chlorine chemicals and equipment.

I looked at bromine, and really didn't see much in the way of benefits from what I would be doing (residential, low usage). If I was looking at a commercial tub, or having heavy bather loads, then I might have been swayed to bromine.
Click to expand...
Well the 3 step bromine plan is nice cause I find tablets will hold bromine when not using the tub so little-to-no maintenance when tub is not used. If tub is not used for a week I generally shock with couple oz of 12% chlorine to get bromine levels back up. Also add about an oz of chlorine after each use.

On your chlorine plan is there daily additions of chlorine when spa is not used?
 

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The simplest and most efficacious way to treat hot tub water is by using chlorine and Aqua Clarity. You won’t have to use all the other products you read about other than the Saltron chlorine generator system. That is it!
 
I appreciate all the replies. I've been quiet while I’ve spent the past 3 days digging deep into the last 10+ years of posts on the various forums by Chem Geek, Vermonteer, and Nitro. I finally think I have a working understanding of the dichlor/bleach method as well as how they can be used with Nature2 and MPS thanks to Chem Geek.

For those using the salt generators, I see its advantages, but it isn’t for me. For those using only dichlor/bleach for sanitation, this requires dealing with hot tub chemistry 4-5 times every week. This is not my idea of a sustainable routine – plus I don’t want that level of FC.

As for those who say Nature2 and MPS do not sanitize, my research shows that the EPA does recognize Nature2 as a sanitizer and the minerals indeed kill bacteria. Yes, to be an EPA approved sanitizer system, you still need FC of .5 ppm, but this is much lower FC than without the Nature2. I’ve also concluded based on research and 10 years of experience with Nature2 that the level of FC can be less – it’s a matter of usage, preferences, and educated risks. I've never have had an issue with bacterial infections while using Nature2 and without a continual level of approved sanitizer. However, I see the value of chlorine and came up with the following routine I'm considering which combines the Nature2 system with the dichlor/bleach system thanks to Chem Geek and Nitro.

I'd appreciate any feedback on the following routine. My main questions:
  • Since I only plan to use bleach weekly or bi-weekly, how much should use (ppm)?
  • Ozonator - How should I adjust my MPS - half? I've read for half for chlorine with daily use and double for infrequent use
  • borates - the concerns make me pause
    • It is not uncommon for pets drinking to result in illness or even death
    • The EU has banned due to health concerns
  • Is it true that the Clorox Regular 7.5% bleach has fewer additives than the 6% bleach? The 6% advertises "Cloromax Technology".

370 Gallon Sundance Spa with built In ozonator & UV

Nature2 Mineral Stick – changed every 4 months
Initial Fill: This should give me a balanced tub with a Saturation Index of -0.04 (without borates)
  • Calcium Hardness - 130 ppm (mine is very low and I have to add calcium)
  • pH – 7.6 (stabilized with jets)
  • Total Alkalinity - 80 ppm (my well water is low and I add baking soda)
  • Borates (undecided) - 50 ppm = 13.5 oz of Boric Acid / 370 gal
  • Dichlor – 10 ppm FC (9 ppm CYA) - 1.7 tbsp / 370 gallons
  • (Nature2 says 1.5 tbsp / 250 gallons which is 13 ppm FC)
The first week: (to get CYA to between 20-30
  • Dichlor - 7 ppm FC (6.3 ppm CYA) – 3.5 tsp / 370 gallons per person hour - 3 doses adds 19 ppm CYA for a total of 28 ppm
Maintenance:
  • MPS - 7 ppm CC registered - 2.5 tbsp / 370 gallons per person hour - OR HALF because of ozonator?
  • Bleach - (weekly or bi-weekly) – 4 ppm - 2.4 oz / 370 gallons (7.5% bleach)

When Needed
  • Bleach - shock – 10 ppm? - 7.7 oz / 370 gallons (7.5% bleach) - w/ added acid first
 
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Krulligo said:
Well the 3 step bromine plan is nice cause I find tablets will hold bromine when not using the tub so little-to-no maintenance when tub is not used. If tub is not used for a week I generally shock with couple oz of 12% chlorine to get bromine levels back up. Also add about an oz of chlorine after each use.

On your chlorine plan is there daily additions of chlorine when spa is not used?
Click to expand...

I dose my spa 4-5 times a week (plus after use) to keep it at a "nice" level. I can go a week or so if I know I am not going to use it, by getting it up to high SLAM levels first.

The problem is with my ozone generator. Ozone depletes CL, so that is what consumes it. If I did not have an ozone generator, I suspect I could easily hold CL for a week without use.

If I am going away for a week, and I raise my CL to high SLAM levels, and close the cover on my spa, it is a fairly sanitary environment (With Aqua Clarity I have no biofilms) so between the initially high CL, the ozone, and the closed spa, when I get back after a week, my CL may be quite low, but my water is clear. I SLAM the tub again, and it is all good to go.
 
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contentedPilgrim said:
I appreciate all the replies. I've been quiet while I’ve spent the past 3 days digging deep into the last 10+ years of posts on the various forums by Chem Geek, Vermonteer, and Nitro. I finally think I have a working understanding of the dichlor/bleach method as well as how they can be used with Nature2 and MPS thanks to Chem Geek.

For those using the salt generators, I see its advantages, but it isn’t for me. For those using only dichlor/bleach for sanitation, this requires dealing with hot tub chemistry 4-5 times every week. This is not my idea of a sustainable routine – plus I don’t want that level of FC.

As for those who say Nature2 and MPS do not sanitize, my research shows that the EPA does recognize Nature2 as a sanitizer and the minerals indeed kill bacteria. Yes, to be an EPA approved sanitizer system, you still need FC of .5 ppm, but this is much lower FC than without the Nature2. I’ve also concluded based on research and 10 years of experience with Nature2 that the level of FC can be less – it’s a matter of usage, preferences, and educated risks. I've never have had an issue with bacterial infections while using Nature2 and without a continual level of approved sanitizer. However, I see the value of chlorine and came up with the following routine I'm considering which combines the Nature2 system with the dichlor/bleach system thanks to Chem Geek and Nitro.

I'd appreciate any feedback on the following routine. My main questions:
  • Since I only plan to use bleach weekly or bi-weekly, how much should use (ppm)?
  • Ozonator - How should I adjust my MPS - half? I've read for half for chlorine with daily use and double for infrequent use
  • borates - the concerns make me pause
    • It is not uncommon for pets drinking to result in illness or even death
    • The EU has banned due to health concerns
  • Is it true that the Clorox Regular 7.5% bleach has fewer additives than the 6% bleach? The 6% advertises "Cloromax Technology".

370 Gallon Sundance Spa with built In ozonator & UV

Nature2 Mineral Stick – changed every 4 months
Initial Fill: This should give me a balanced tub with a Saturation Index of -0.04 (without borates)
  • Calcium Hardness - 130 ppm (mine is very low and I have to add calcium)
  • pH – 7.6 (stabilized with jets)
  • Total Alkalinity - 80 ppm (my well water is low and I add baking soda)
  • Borates (undecided) - 50 ppm = 13.5 oz of Boric Acid / 370 gal
  • Dichlor – 10 ppm FC (9 ppm CYA) - 1.7 tbsp / 370 gallons
  • (Nature2 says 1.5 tbsp / 250 gallons which is 13 ppm FC)
The first week: (to get CYA to between 20-30
  • Dichlor - 7 ppm FC (6.3 ppm CYA) – 3.5 tsp / 370 gallons per person hour - 3 doses adds 19 ppm CYA for a total of 28 ppm
Maintenance:
  • MPS - 7 ppm CC registered - 2.5 tbsp / 370 gallons per person hour - OR HALF because of ozonator?
  • Bleach - (weekly or bi-weekly) – 4 ppm - 2.4 oz / 370 gallons (7.5% bleach)

When Needed
  • Bleach - shock – 10 ppm? - 7.7 oz / 370 gallons (7.5% bleach) - w/ added acid first
Click to expand...

Using beach takes me 5 minutes, 4-5 times a week for a hot tub that I know is not going to get my family sick is time well spent for me, and an easily maintainable solution. You are adding MPS at a rate of 2.5 tbsp / 370 gallons per person hour. So you are already adding something each time you use the tub, so this is hardly a "set it and forget it" solution.

Why are you concerned about the levels of FC required? They are plenty safe. Given the fact that you are more than willing to use MPS, which has been shown to cause skin irritation in good number of people, possibly also acting as a sensitizing agent, why the concern for CL?

MPS is not a sanitizer
Nature2 is a sanitizer, but in my opinion, not an EFFECTIVE sanitizer. The use of silver has been discussed numerous times on these boards.

Nature2 still requires a certain level of FC in the water, so you are going to have to test for that on a fairly frequent basis.

How is your ozone system configured? Do you have a dedicated circulation pump that runs 24/7 or is it a batch system that works only during the filter cycle. There is a big difference between the two. One puts a relatively constant amount of ozone into all of the water. The other puts a large amount of ozone into a small batch of the water, and then removes any excess. How that impacts your oxidation needs, depends on how your system is set up.

As you said, the decision to use Nature2 is your personal preference, but given the above schedule and chemical regiment, I don't see a reduction in effort, I do see a reduction in sanitation, and an increase in cost.
 
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phonedave said:
Using beach takes me 5 minutes, 4-5 times a week for a hot tub that I know is not going to get my family sick is time well spent for me, and an easily maintainable solution. You are adding MPS at a rate of 2.5 tbsp / 370 gallons per person hour. So you are already adding something each time you use the tub, so this is hardly a "set it and forget it" solution.
Click to expand...
Adding chemicals each time I use the tub is one thing. For once a week usage weeks, I don't want to have to deal with the hot tub. I could have 24" of snow on the cover and weekends may be the only time to deal with it.

phonedave said:
Why are you concerned about the levels of FC required? They are plenty safe. Given the fact that you are more than willing to use MPS, which has been shown to cause skin irritation in good number of people, possibly also acting as a sensitizing agent, why the concern for CL?
Click to expand...
I personally don't want FC in any measurable amount in the water I soak in. The dangers of FC, chloramines, and chloroform, and other chlorine disinfection by-products (DBPs) are well-known. Chloroform in particular is inhalded and absorbed through the skin. I know the arguments regarding their low level, but my personal preference is to stay away from them. I am OK using chlorine to kill bacteria on an as needed basis - I just want to keep it to a minimum. I don't have a lot of links or studies to cite. Here is one study which talks about the impact of chlorine in swimming pools on rats and another study measuring chloroform intake. This answer is strictly to answer your question, not to start a debate.

MPS doesn't cause skin irritation for my family. In the end, its use trades off a build-up of sulfates versus chlorides, as far as I can tell.

phonedave said:
MPS is not a sanitizer
Nature2 is a sanitizer, but in my opinion, not an EFFECTIVE sanitizer. The use of silver has been discussed numerous times on these boards.

Nature2 still requires a certain level of FC in the water, so you are going to have to test for that on a fairly frequent basis.
Click to expand...

As I understand it, it's the combination of Nature2 plus MPS which is a sanitizer.

Nature2 (literature) requires 0.5 ppm FC - but I'll get by (and have) with none - due to the ozonator and UV. The Nature2/Ozone/UV can do the job based on experience. If we're using the hot tub daily, I may reconsider.

In the beginning, I'll test to see how much is needed to have a barely detectable FC level the next day. On a maintenance basis, I'll check FC once a week - likely the soak day after the weekly dose.

phonedave said:
How is your ozone system configured? Do you have a dedicated circulation pump that runs 24/7 or is it a batch system that works only during the filter cycle. There is a big difference between the two. One puts a relatively constant amount of ozone into all of the water. The other puts a large amount of ozone into a small batch of the water, and then removes any excess. How that impacts your oxidation needs, depends on how your system is set up.
Click to expand...
The ozonator runs with the circulation pump. It's factory default is to run 8 hours per day, but can be programmed for any amount.

phonedave said:
As you said, the decision to use Nature2 is your personal preference, but given the above schedule and chemical regiment, I don't see a reduction in effort, I do see a reduction in sanitation, and an increase in cost.
Click to expand...
Cost is not the driver for this - it's a drop in the bucket compared to the tub and far better than the system they want to sell (Frog @Ease). Adding MPS after each soak (or once a week if no soaking) is definitely less work than adding chlorine throughout the week, which is what I understand the system requires. The reduction in sanitation is indeed intended as the tradeoff for fewer chemicals - especially the halogens. With regard to what we put in our bodies, to each their own. I appreciate the discussion and the research I have to do to answer it.
 
contentedPilgrim said:
Here is one study which talks about the impact of chlorine in swimming pools on rats and another study measuring chloroform intake. This answer is strictly to answer your question, not to start a debate.
Click to expand...
No debate here. We do it different and that study does not apply. It's apples and oranges. Our FC is less harsh than tap water that you drink and shower in.
 
contentedPilgrim said:
Adding chemicals each time I use the tub is one thing. For once a week usage weeks, I don't want to have to deal with the hot tub. I could have 24" of snow on the cover and weekends may be the only time to deal with it.
Click to expand...

Understood - but for the record, if you have 24" of snow on your cover, you should push some of that off.

I personally don't want FC in any measurable amount in the water I soak in. The dangers of FC, chloramines, and chloroform, and other chlorine disinfection by-products (DBPs) are well-known. Chloroform in particular is inhalded and absorbed through the skin. I know the arguments regarding their low level, but my personal preference is to stay away from them. I am OK using chlorine to kill bacteria on an as needed basis - I just want to keep it to a minimum. I don't have a lot of links or studies to cite. Here is one study which talks about the impact of chlorine in swimming pools on rats and another study measuring chloroform intake. This answer is strictly to answer your question, not to start a debate.
Click to expand...

I won't debate it then. I appreciate the insight into your decision making process.

MPS doesn't cause skin irritation for my family. In the end, its use trades off a build-up of sulfates versus chlorides, as far as I can tell.
Click to expand...

The jury is out on if MPS allergies are acquired due to sensitization, or if they are inherent to the person. Lot's of people do just fine with them, so it is not a horrible risk.

As I understand it, it's the combination of Nature2 plus MPS which is a sanitizer.
Click to expand...

Nature2 is the (albeit very weak) sanitizer. MPS is the oxidizer. You need both.

Nature2 (literature) requires 0.5 ppm FC - but I'll get by (and have) with none - due to the ozonator and UV. The Nature2/Ozone/UV can do the job based on experience. If we're using the hot tub daily, I may reconsider.
Click to expand...

If you are only using the tub once a week, you may indeed get by with that. But any more usage than that is a big risk. Nature2 is a very weak sanitizer, ozone and UV are only working on whatever gets into the Ozone and UV mechanism. In other words, if there is something in your tub (lets be semi gross here some solid organic material from somebody) here is what is going to happen. It will get lodged in your filter, it will never get close to the ozone or UV treatments. The mild Nature2 will do a little, but that substance is going to grow and dump bacteria into the water where it will find nooks and crannies to breed in.

In the beginning, I'll test to see how much is needed to have a barely detectable FC level the next day. On a maintenance basis, I'll check FC once a week - likely the soak day after the weekly dose.
Click to expand...

Just because you have FC in the water does not mean you have nothing actively growing in the water too.

The ozonator runs with the circulation pump. It's factory default is to run 8 hours per day, but can be programmed for any amount.
Click to expand...

Normally a dedicated circulation pump runs 24 hours. A jet pump that is also used for filtering is on the 8 hour timer.

Cost is not the driver for this - it's a drop in the bucket compared to the tub and far better than the system they want to sell (Frog @Ease). Adding MPS after each soak (or once a week if no soaking) is definitely less work than adding chlorine throughout the week, which is what I understand the system requires. The reduction in sanitation is indeed intended as the tradeoff for fewer chemicals - especially the halogens. With regard to what we put in our bodies, to each their own. I appreciate the discussion and the research I have to do to answer it.
Click to expand...

Discussion is good. Research is good too. As far as what chemicals are around us, I am pretty in tune to that I well, different people make different decisions.
 
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Newdude said:
No debate here. We do it different and that study does not apply. It's apples and oranges. Our FC is less harsh than tap water that you drink and shower in.
Click to expand...
The point is that with chloroform (in particular) and chlorine in general, we're dealing with substances that are known carcinogens, harm the kidneys and liver, and can impair cognitive function. We're also dealing with long term exposure. To your point about drinking and bathing in tap water, I do neither and bathing is a known source of uptake of HKs and Chlorform as shown in these research articles: Dermal uptake of chloroform and haloketones during bathing and ...Dermal Absorption of Chloroform by Humans following Bath Water Exposures.

So, I have no judgment on other who choose the risks associated with chlorine, but to tell me there are no dangers amounts to putting one's head in the sand. We make choices and take calculated risks. My choices are no less valid than yours.
 
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