Peroxide dosing with automation

PjPoolguy

In The Industry
Jan 9, 2024
11
Colorado
This one is tricky- residential spa....made of copper. Cant use chlorine, so its set up with an ozone generator and peroxide. Owner and service techs would like this set up on automation. They are set up with a pentair Intellichem unit, which isnt dosing well- from what ive found, peroxide doesnt neatly translate to ORP, and the controller has no idea when to send the peroxide. Service techs show up once a week and shock it to 100ppm of peroxide because its testing zero ppm of peroxide. 1500 gallon copper spa. Anybody have experience with dosing peroxide regularly? I have a controller line that uses a peroxide probe, but it costs $6000, which is more than the owner wants to spend on this. That would obviously help out with automation, but I'd like to figure out a dosage per unit of time, which they could set and forget. I told them to show up three days in a row and dose it, test, figure out how much theyve used over 3 days, do some math and time the system to that frequency.

Any help is seriously seriously appreciated.
 
ORP should register higher with higher peroxide levels. My guess is the dosing isn’t high enough.

What percentage peroxide are you putting into the tank?

Note that peroxide degrades under neutral and high pH conditions into water and oxygen gas. The amount of O2 evolved can be quite substantial. The tank needs to be properly vented to avoid explosive overpressures.

Peroxide is also a lousy sanitizer and typically needs levels that are fairly high to deal with pathogens. That can often mean levels high enough to cause skin irritation. My suggestion would be to make sure the spa plumbing is properly purged with Ahhsome to remove biofilms and then to very regularly dump the spa. Without a fast and potent sanitizer like chlorine or bromine, the owner of this tub is flirting with seriously bad waterborne illnesses. Pseudomonas skin infections are a nuisance … respiratory legionella infection can be fatal.
 
We do not really have a lot of experience dealing with peroxide.

Hydrogen peroxide disproportionates to form water and oxygen.

The rate of decomposition increases with rise in temperature.

2H2O2 --> 2H2O + O2

The hydrogen peroxide can react with the ozone and produce oxygen and water.

H2O2 + O3 --> H2O + 2O2

How much ozone does the ozonator produce?

If you need to maintain the peroxide levels, then you need to test often and adjust as needed.

The breakdown of peroxide can be affected by tub use, ozone levels etc.

Getting a commercial UV system would help keep the water sanitized, but it might cause a faster breakdown of the peroxide.

You might need a Baquaspa type product to provide a sanitizer level.

What is the concern with using chlorine?

Are you worried that the copper will get oxidized?

The hydrogen peroxide and ozone probably pose as much or more corrosion/oxidation risk as using chlorine.

Ozone and hydrogen peroxide are stronger oxidizers than chlorine.

Pools and spas have heaters with copper heat exchangers and they do ok as long as the pH is kept high enough.

If the pH is kept up, the copper forms a patina of copper oxide, which protects the copper from oxidation.

You can see this by comparing a new shiny penny/cent to an old penny that is brown.

The brown is copper oxide.

If the pH is allowed to go too low, the copper oxide is stripped off and the molecular/elemental copper is exposed.

What does the copper look like?

Does it look like elemental copper or is it green or brown or what?

Is the copper sealed with any type of sealer?

1707238423387.png

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1707238472004.png
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1707238543001.png

1707239530361.png
 
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ORP should register higher with higher peroxide levels. My guess is the dosing isn’t high enough.

What percentage peroxide are you putting into the tank?

Note that peroxide degrades under neutral and high pH conditions into water and oxygen gas. The amount of O2 evolved can be quite substantial. The tank needs to be properly vented to avoid explosive overpressures.

Peroxide is also a lousy sanitizer and typically needs levels that are fairly high to deal with pathogens. That can often mean levels high enough to cause skin irritation. My suggestion would be to make sure the spa plumbing is properly purged with Ahhsome to remove biofilms and then to very regularly dump the spa. Without a fast and potent sanitizer like chlorine or bromine, the owner of this tub is flirting with seriously bad waterborne illnesses. Pseudomonas skin infections are a nuisance … respiratory legionella infection can be fatal.
27%. Heres the product:
1707240094042.png


I did manage to find a link to the SDS: https://www3.epa.gov/pesticides/chem_search/ppls/003432-00083-20050920.pdf

Its just Peroxide. Ive consulted some float tank businesses regarding the management of their tanks, which typically use the same peroxide+ozon setup, and as far as I can tell the best practice to avoid illnesses is a high concentration of Peroxide- I want these to be at 100ppm, itchy skin or not. Float tanks have virtually zero generalized procedures and manufacturers do not provide any guidance at all. I agree with you and have anxiety about people getting sick in commercial float tanks in particular, which typically arent even covered under the local health codes and dont get inspected. Im expecting a very sad story to change that in the near future. They do have the benefit of enough Epsom Salt to raise the specific gravity to 1.24-1.3, and that salt certainly SHOULD help.

Anyways- this copper spa....

I am wondering if the controller setup itself is somehow mechanically failing to deliver peroxide into the water, because Peroxide should be affecting the ORP and the controller should be feeding it. I might make a site visit to get more information.
 
We do not really have a lot of experience dealing with peroxide.

Hydrogen peroxide disproportionates to form water and oxygen.

The rate of decomposition increases with rise in temperature.

2H2O2 --> 2H2O + O2

The hydrogen peroxide can react with the ozone and produce oxygen and water.

H2O2 + O3 --> H2O + 2O2

How much ozone does the ozonator produce?

If you need to maintain the peroxide levels, then you need to test often and adjust as needed.

The breakdown of peroxide can be affected by tub use, ozone levels etc.

Getting a commercial UV system would help keep the water sanitized, but it might cause a faster breakdown of the peroxide.

You might need a Baquaspa type product to provide a sanitizer level.

What is the concern with using chlorine?

Are you worried that the copper will get oxidized?

The hydrogen peroxide and ozone probably pose as much or more corrosion/oxidation risk as using chlorine.

Ozone and hydrogen peroxide are stronger oxidizers than chlorine.

Pools and spas have heaters with copper heat exchangers and they do ok as long as the pH is kept high enough.

If the pH is kept up, the copper forms a patina of copper oxide, which protects the copper from oxidation.

You can see this by comparing a new shiny penny/cent to an old penny that is brown.

The brown is copper oxide.

If the pH is allowed to go too low, the copper oxide is stripped off and the molecular/elemental copper is exposed.

What does the copper look like?

Does it look like elemental copper or is it green or brown or what?

Is the copper sealed with any type of sealer?

View attachment 553224

_________________________________________________________________

View attachment 553225
_______________________________________________________________________________________

View attachment 553226

View attachment 553230

I wonder if the heat of the spa is causing a rapid loss of peroxide....that would seem to track with the issues theyre running into.

The chief concern of using chlorine is the oxidation of the copper. I appreciate the insight- there might be a way to use chlorine and avoid oxidation if the pH is kept under control. I found a company that makes copper spas, and am going to ask them how they recommend caring for them.

As far as Baquaspa, if you read the SDS ( https://leisurepoolinc.com/wp-content/uploads/2019/04/BAQUASPA-Oxidizer-SDS.pdf ) it appears to be %7.5 Hydrogen Peroxide.
 
[This product] [POOL ELEGANCE SANITIZER] [sanitizer] is rt_ .ered as . Nimming pool, spa and hot tub sanitizer, not as a disinfectant.]
DIRECTIONS FOR USE
It is a violation of federal law to use this product in a manner inconsistent with ns labeling.

Important - POOL ELEGANCE SANITIZER [sanitizer] is incompatible with chlOrinating chemical products.

Consult your authorized [Dealer of POOL ELEGANCE SANITIZER]

[POOL ELEGANCE SANITIZER Dealer] for information on balancing your pool water.

[Start up] [Treating the pool]

[Pools Previously Treated with Chlorinating Chemicals

Check with chlorine test kit for free and combined chlorine prior to the beginning of neutralization.

To destroy chlorine, add chlorine neutralizer per label directions.

Filter overnight.

Check with chlorine test kit.

If free chlorine is detected, repeat neutralizer treatment.

(Note to reviewer: Directions may be lettered or numbered on final printed labeling.)

Freshly Filled and Dechlorinated Pools _.'

Start up with POOL ELEGANCE SANITIZER [sanitizer}

Note: If the pool water contains algae or is hazy, consult the problem-solving section of the "Pool [Owner's] [Care] Guide," available from your authorized [Dealer of POOL ELEGANCE SANITIZER] [POOL ELEGANCE SANITIZER Dealer]

• Backwash or clean pool filter.

Check pool pH; adjust to 7.0 -7.8 if necessary.

• Add POOL ELEGANCE SANITIZER [sanitizer] to give a content of 50 ppm (112 gallon producUl0,000 gallons of [pool] water).

• After 24 hours, check pH and POOL ELEGANCE SANITIZER [sanitizer] concentration with the test kit for POOL ELEGANCE SANITIZER [sanitizer] and adjust if necessary {Maintenance} Normal Pool Routine

• Every week, check POOL ELEGANCE SANITIZER [sanitizer] concentration and pH.

• Maintain POOL ELEGANCE SANITIZER [sanitizer] concentration at about 50 ppm.

If concentration falls 10 ppm or more, add a top-up dose.

The level should not be allowed to drop below 30 ppm.

For example, to raise the POOL ELEGANCE SANITIZER [sanitizer] level 10ppm, add [16 oz.] [1 pint] per 10,000 gallons of [pool]
water.

Consult the booklet, "The Pool [Owner's] [Care] Guide for POOL ELEGANCE SANITIZER [sanitizer]," for calculation instructions.
NOTE: POOL ELEGANCE SANITIZER [sanitizer] AND CHLORINE ARE INCOMPATIBLE.

Refer to the Pool [Owner's] [Care] Guide for POOL ELEGANCE SANITIZER [sanitizer] for information on how to deal with accidental chlorination.

*Bracketed text denotes alternate maJ1(eting Janguage and use directions.
.,.-, -~
Problem-SalvI. ,nd Suppmental Pool Information, Do not use in freestanding spaslhot tubs.

Do not use in unpainted plaster pools previously exposed to metals which may cause staining.

POOL ELEGANCE SANITIZER [sanitizer] is not compatible with many detergents and some supplemental algaecides (such as those based on copper).

If algae development, cloudiness, or pool problems occur or additional information on water quality is desired, consult "The Pool [Owner's] [Care] Guide for POOL ELEGANCE SANITIZER," available from your [Authorized Dealer of POOL ELEGANCE
SANITIZER [sanitizer]] [POOL ELEGANCE SANITIZER [sanitizer] Authorized Dealer].]

[Treating the spa or hot tub Important - POOL ELEGANCE SANITIZER [sanitizer] is incompatible with chlorinating
[and] [or] brominating chemical products. ._ .

(Note to reviewer: Directions may be lettered or numbered on final printed labeling.)

Start up with POOL ELEGANCE SANITIZER [sanitizer}

• Remove chlorine or bromine source and disconnect feeder.

Discontinue use of ionizers and electrochlorinators if present.

• Drain existing water in spa.

• Clean [spa](hot tub] [surface] [with water] [and filter].

• Fill [spa](hot tub] [surface] with water.

• [Bring a sample of [spa] [hot tub] water to your POOL ELEGANCE SANITIZER [sanitizer] Authorized dealer] [Authorized Dealer of POOL ELEGANCE SANITIZER [sanitizer]] to check it for proper water balance.] [Have your authorized dealer of POOL ELEGANCE SANITIZER [sanitizer] check your water for proper water balance.]

• After [your] [spa] [hot tub] water has been balanced, add POOL ELEGANCE SANITIZER [sanitizer] to give a concentration of 50 ppm.

(1 [fl.] oz. of product [for] [per] 150 gallon of [spa] [hot tub] water).

• Circulate [water] [for] 30 minutes then check the POOL ELEGANCE SANITIZER [sanitizer] [Ieveij [concentration] [and]. Adjust if necessary.

[Normal} SpaIHot Tub MaIntenance

• Every week, check POOL ELEGANCE SANITIZER [sanitizer] concentration and
pH.

Adjust if necessary.

• The [level oij POOL ELEGANCE SANITIZER [sanitizer] [level] should be maintained between 30 and 50 ppm. [When the level of POOL ELEGANCE SANITIZER is 30 ppm or less, add enough POOL ELEGANCE SANITIZER to bring the level up to 50 ppm.]

• The [POOL ELEGANCE SANITIZER level] [spa's level of POOL ELEGANCE SANITIZER] should never [be allowed to] drop below 30 ppm.

• To raise the [POOL ELEGANCE SANITIZER] sanitizer level 10 ppm, add 0.2 oz. per 150 gal. of [spa] water.]
 
Last edited:
[This product] [POOL ELEGANCE SANITIZER] [sanitizer] is rt_ .ered as . Nimming pool, spa and hot tub sanitizer, not as a disinfectant.]
DIRECTIONS FOR USE
It is a violation of federal law to use this product in a manner inconsistent with ns labeling.

Important - POOL ELEGANCE SANITIZER [sanitizer] is incompatible with chlOrinating chemical products.

Consult your authorized [Dealer of POOL ELEGANCE SANITIZER]

[POOL ELEGANCE SANITIZER Dealer] for information on balancing your pool water.

[Start up] [Treating the pool]

[Pools Previously Treated with Chlorinating Chemicals

Check with chlorine test kit for free and combined chlorine prior to the beginning of
neutralization.

To destroy chlorine, add chlorine neutralizer per label directions.

Filter overnight.

Check with chlorine test kit.

If free chlorine is detected, repeat neutralizer treatment.

(Note to reviewer: Directions may be lettered or numbered on final printed labeling.)

Freshly Filled and Dechlorinated Pools _.'

Start up with POOL ELEGANCE SANITIZER [sanitizer}

Note: If the pool water contains algae or is hazy, consult the problem-solving section of the "Pool [Owner's] [Care] Guide," available from your authorized [Dealer of POOL ELEGANCE SANITIZER] [POOL ELEGANCE SANITIZER Dealer]

• Backwash or clean pool filter.

Check pool pH; adjust to 7.0 -7.8 if necessary.

• Add POOL ELEGANCE SANITIZER [sanitizer] to give a content of 50 ppm (112 gallon producUl0,000 gallons of [pool] water).

• After 24 hours, check pH and POOL ELEGANCE SANITIZER [sanitizer] concentration with the test kit for POOL ELEGANCE SANITIZER [sanitizer] and adjust if necessary {Maintenance} Normal Pool Routine

• Every week, check POOL ELEGANCE SANITIZER [sanitizer] concentration and pH.

• Maintain POOL ELEGANCE SANITIZER [sanitizer] concentration at about 50 ppm.

If concentration falls 10 ppm or more, add a top-up dose.

The level should not be allowed to drop below 30 ppm.

For example, to raise the POOL ELEGANCE SANITIZER [sanitizer] level 10ppm, add [16 oz.] [1 pint] per 10,000 gallons of [pool]
water.

Consult the booklet, "The Pool [Owner's] [Care] Guide for POOL ELEGANCE SANITIZER [sanitizer]," for calculation instructions.
NOTE: POOL ELEGANCE SANITIZER [sanitizer] AND CHLORINE ARE INCOMPATIBLE.

Refer to the Pool [Owner's] [Care] Guide for POOL ELEGANCE SANITIZER [sanitizer] for information on how to deal with accidental chlorination.

*Bracketed text denotes alternate maJ1(eting Janguage and use directions.
.,.-, -~
Problem-SalvI. ,nd Suppmental Pool Information, Do not use in freestanding spaslhot tubs.

Do not use in unpainted plaster pools previously exposed to metals which may cause staining.

POOL ELEGANCE SANITIZER [sanitizer] is not compatible with many detergents and some supplemental algaecides (such as those based on copper).

If algae development, cloudiness, or pool problems occur or additional information on water quality is desired, consult "The Pool [Owner's] [Care] Guide for POOL ELEGANCE SANITIZER," available from your [Authorized Dealer of POOL ELEGANCE
SANITIZER [sanitizer]] [POOL ELEGANCE SANITIZER [sanitizer] Authorized Dealer].]

[Treating the spa or hot tub Important - POOL ELEGANCE SANITIZER [sanitizer] is incompatible with chlorinating
[and] [or] brominating chemical products. ._ .

(Note to reviewer: Directions may be lettered or numbered on final printed labeling.)

Start up with POOL ELEGANCE SANITIZER [sanitizer}

• Remove chlorine or bromine source and disconnect feeder.

Discontinue use of ionizers and electrochlorinators if present.

• Drain existing water in spa.

• Clean [spa](hot tub] [surface] [with water] [and filter].

• Fill [spa](hot tub] [surface] with water.

• [Bring a sample of [spa] [hot tub] water to your POOL ELEGANCE SANITIZER [sanitizer] Authorized dealer] [Authorized Dealer of POOL ELEGANCE SANITIZER [sanitizer]] to check it for proper water balance.] [Have your authorized dealer of POOL ELEGANCE SANITIZER [sanitizer] check your water for proper water balance.]

• After [your] [spa] [hot tub] water has been balanced, add POOL ELEGANCE SANITIZER [sanitizer] to give a concentration of 50 ppm.

(1 [fl.] oz. of product [for] [per] 150 gallon of [spa] [hot tub] water).

• Circulate [water] [for] 30 minutes then check the POOL ELEGANCE SANITIZER [sanitizer] [Ieveij [concentration] [and]. Adjust if necessary.

[Normal} SpaIHot Tub MaIntenance

• Every week, check POOL ELEGANCE SANITIZER [sanitizer] concentration and
pH.

Adjust if necessary.

• The [level oij POOL ELEGANCE SANITIZER [sanitizer] [level] should be maintained between 30 and 50 ppm. [When the level of POOL ELEGANCE SANITIZER is 30 ppm or less, add enough POOL ELEGANCE SANITIZER to bring the level up to 50 ppm.]

• The [POOL ELEGANCE SANITIZER level] [spa's level of POOL ELEGANCE SANITIZER] should never [be allowed to] drop below 30 ppm.

• To raise the [POOL ELEGANCE SANITIZER] sanitizer level 10 ppm, add 0.2 oz. per 150 gal. of [spa] water.]
Hmmm it appears to be a "Biguanide". I wonder if these sanitation systems oxidize copper? Preliminary search says no....

I have zero experience with Biguanides.

(Edit- was reading and replying when you responded!)
 

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The Shock is hydrogen Peroxide.

The Sanitizer is Biguanide.

The system requires that the sanitizer levels be maintained.

POOL ELEGANCE SANITIZER [sanitizer] is not compatible with many detergents and some supplemental algaecides (such as those based on copper).
This says that copper is not compatible, but I do not know what the issue is with copper and how it might react to the biguanide.

1707243116828.png
 
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I meant the Biguanide systems. Would those oxidize copper? I couldn't find anything conclusive.
I do not know what the reaction is.

The instructions say "POOL ELEGANCE SANITIZER [sanitizer] is not compatible with many detergents and some supplemental algaecides (such as those based on copper)".

What does the copper look like?
 
Is the copper spa in an owner occupied residence or a short term rental AirBNB.
 
The Shock is hydrogen Peroxide.

The Sanitizer is Biguanide.

The system requires that the sanitizer levels be maintained.


This says that copper is not compatible, but I do not know what the issue is with copper and how it might react to the biguanide.

View attachment 553244

I do not know what the reaction is.

The instructions say "POOL ELEGANCE SANITIZER [sanitizer] is not compatible with many detergents and some supplemental algaecides (such as those based on copper)".

What does the copper look like?
Not sure yet. The guys are heading there Friday and I'll request some photos.
 
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