Free And Total Chlorine Question

[styro]

Hi,

I just notice today after a month of smooth water chemistry going my Free and total Chlorine they out of range.

The difference between f.ch and t.ch past month was always around 0.45-0.50

Today my numbers are:

f.ch - 3.46

t.ch - 4.36

PH - 7.7

TA - 56

Hardens last measure was 140

CYA - 26

temperature - 95F

Spa = 325 gallons

Like you see the total and free chlorine are almost 1.0

What happen to the T.ch and F.ch?

What to do to avoid to happen in the future again and please let me know what to do now?

Superchlorinate?

Please advise.

Adam

[gman]

My initial thoughts are that you may have just had a larger amount of contaminant in the water (relative to your "average") which could have caused the increase in CC. I would add a bit more chlorine (relative to your "usual" chlorine demand amount) than you normally would to replace your used chlorine and help handle the added contaminants. You may also want to check your filters. They may need to be cleaned. If you try these two options, I think your CC will return to its usual 0.5 reading.

gman

[chem geek]

Also, if you ever use non-chlorine shock (MPS), it will register as Combined Chlorine (CC) unless you use a special interference remover.

Your numbers sound like they are from an instrument that either you have or are getting from the pool store, not from the Taylor K-2006 FAS-DPD chlorine test. So I can't comment on the accuracy of the instrument being used.

[quantumchromodynamics]

Some of the LaMotte Color Q test kits report at this level of precision. I would guess that that would probably be the test kit.

[styro]

Some of the LaMotte Color Q test kits report at this level of precision. I would guess that that would probably be the test kit.

Yes you right I'm using Color Q tester and so far for a year of usage I haven't seen before that big difference.

Yesterday 0.5 and today 0.9

I do the test at least 2 times a week with Color Q and the rest of days with a strips.

From the first poster gman I would like to fallow the idea of adding extra chlorine.

Normally I do add 60 ml of bleach 6% every evening without soak and

With soak for one person 85ml for 2 people 100ml.

Please give me example how much extra I should add to get rid off extra contaminant.

Thanks

Adam

[chem geek]

Since this is a spa, another thought is that you should be doing your measurements just before your next soak. If you measure right after a soak, which is soon after adding more chlorine, it is expected to see Combined Chlorine (CC) as this takes some hours to oxidize, especially for urea which would normally take days were it not for hot spa temperatures.

[styro]

Since this is a spa, another thought is that you should be doing your measurements just before your next soak. If you measure right after a soak, which is soon after adding more chlorine, it is expected to see Combined Chlorine (CC) as this takes some hours to oxidize, especially for urea which would normally take days were it not for hot spa temperatures.

Chem geek,

I do add bleach at the end off soak, mostly evenings.

I do measure the chlorine level in the mornings.

What is your suggestion to avoid next time rising of the Total chlorine?

Thanks

Adam

[gman]

Some of the LaMotte Color Q test kits report at this level of precision. I would guess that that would probably be the test kit.

Yes you right I'm using Color Q tester and so far for a year of usage I haven't seen before that big difference.

Yesterday 0.5 and today 0.9

I do the test at least 2 times a week with Color Q and the rest of days with a strips.

From the first poster gman I would like to fallow the idea of adding extra chlorine.

Normally I do add 60 ml of bleach 6% every evening without soak and

With soak for one person 85ml for 2 people 100ml.

Please give me example how much extra I should add to get rid off extra contaminant.

Thanks

Adam

Adam,

I would try increasing the amount of chlorine you normally add by about 30 - 35 %. Try it for one night. So, if you're not using your tub and normally add 60 ml in the evening, try adding 78 - 81 ml of bleach. If one person has used the tub and you normally add 85 ml, try adding about 110 - 115 ml. If two people have used the tub, then try adding 130 - 135 ml, instead of the usual 100 ml. Wait until morning to test. See if you get any reduction in the amount of CC. You might try keeping your FC level a bit closer to 5 ppm for a while and see if that does not resolve your problem. I would expect the higher chlorine level will resolve your problem, but if it does not, remember to clean your filters and see if that makes a difference.

BTW, I have a 540 gal tub. I have been using Nitro's Dichlor/Bleach method with wonderful results. I don't use the test strips. I use the Taylor drop test kit. Whenever I re-fill my tub, I test daily to make sure my water is balanced and stable. Once stable, I test a little less often...but not that much less (even though I've gotten pretty good at estimating the amount of bleach needed after each user load. I still test regularly just to make sure I'm maintaining my numbers. I try to keep my FC close to 5 ppm. I don't mind if the FC goes a bit higher (6 ppm). I have not been able to detect any noticeable smell of chlorine until the level gets closer to 7 ppm. My CC has not been over 0.5. I would say it's usually less*. My water is beautiful and safe.

*With the Taylor Test Kit, you can test using a 25 ml sample or a 10 ml sample. The 25 ml sample gives results in .2 ppm, while the 10 ml sample gives results in .5 ppm. Initially I used the 25 ml protocol regularly to get more accurate FC results. I've stopped using the 25 ml protocol just to save on the reagent. I became pretty familiar with the color results in the 25 ml protocol. So when I use the 10 ml sample protocol, I can easily tell that the CC is actually under the .5 ppm range that the 10 ml sample would indicate.

Good luck with your water.

gman

[styro]

Hi,

I did incrise the amount off chlorine by super chlorinate last night to 10 ppm with Lithium Hypo.

As a result this morning my numbers are:

PH - 7.8

TA - 50

T.ch - 9.61

F.ch - 8.47

----------------

1.14

The difference is even higher = 1.14

and I feel some smell from the water since I've notice slight difference between T.ch and f.ch few days ago.

What I should do I do not want to change my water since is only 1 month old.

Thanks for any suggestions.

Adam

[styro]

I just run over one site explaining Breakpoint Chlorination

Its stated:

Determine the number of gallons of pool water to be treated and the

percentage of available chlorine in the product that will be used to superchlorinate the pool.

Calculate the amount of chlorine needed by weight, or refer to a standard chart or a chart provided by the chlorine manufacturer.

Amount of available chlorine necessary to raise the chlorine level 1 ppm per 10,000 gallons of pool water

1.5 cups

10%

sodium hypochlorite

1.3 cups

12%

sodium hypochlorite

1 cup

15%

sodium hypochlorite

2.25 oz

60%

sodium dichloro-s-triazinetrione

2 oz

65%

calcium hypochlorite

1.5 oz

85%

trichloro-s-triazinetrione

1.3 oz

100%

elemental gas chlorine

For example: If free available chlorine is 1.0 ppm and total available chlorine is 1.5 ppm, the difference (combined available chlorine) is 0.5 ppm. Multiply 0.5 by 10 to determine that 5 ppm of chlorine must be added to the water in order to reach breakpoint. You know that the pool in question contains 25,000 gallons of water, and you plan to superchlorinate using 10% available sodium hypochlorite. By following the chart and inserting the appropriate numbers into the formula, you can determine that 1 gallon of 12% sodium hypochlorite must be added to a 25,000 gallon pool, to eliminate 0.5 ppm of combined chlorine.

(1.5 cups) (1 ppm) (10,000 gallons)

(1.3 cups) (5 ppm) (2.5) = 16.25 cups ÷ 16 = 1 gallon

My spa is 325 galons.

1.14 todays differece between F.ch and T.ch x10 = 11.4

I have to add enough chlorine to reduce that break point.

In my case please correct me if I'm wrong

I do add 2 oz calcium Hypo(56g)x 11.4ppm x 0.325 gal= 207.48g

I think I should add 208g of calcium hypo 65%

Thanks for looking

Adam

[quantumchromodynamics]

No, do not add 208 grams of cal hypo. That would increase your FC by 104 ppm.

You can use some MPS to oxidize contaminants without adding more chlorine.

Also, be sure to clean your filter

If chloramines are only an occasional problem, then the use of MPS as needed should be sufficient.

If chloramines are a persistent problem, then you might want to consider adding Ozone or UV.

Also, the "10 X the CC level" breakpoint formula is incorrect.

[styro]

No, do not add 208 grams of cal hypo. That would increase your FC by 104 ppm.

You can use some MPS to oxidize contaminants without adding more chlorine.

Also, be sure to clean your filter

If chloramines are only an occasional problem, then the use of MPS as needed should be sufficient.

If chloramines are a persistent problem, then you might want to consider adding Ozone or UV.

I do have ozonator ranning 4x 1hrs per/day.

I did clean my filters.

Since I'm in Canada I do not know what is MPS.

Can you be more specific what I should l look for.

Thanks

Adam

[quantumchromodynamics]

Look for Potassium peroxymonosulfate (also known as MPS or potassium monopersulfate).

You could also increase your filtration and ozonator run times.

[waterbear]

I have not seen this addresses so....

Try shocking in the morning and leave the spa uncovered until the FC drops back to normal with the jets going. To get rid of CC requires a combination of "breakpoint" chlorine levels, sunlight, and gassing off of disinfection byproducts.

Many people make the mistake of shocking at night and/or covering the spa. Not sure if this is your case but I suspect it might be.

[styro]

I have not seen this addresses so....

Try shocking in the morning and leave the spa uncovered until the FC drops back to normal with the jets going. To get rid of CC requires a combination of "breakpoint" chlorine levels, sunlight, and gassing off of disinfection byproducts.

Many people make the mistake of shocking at night and/or covering the spa. Not sure if this is your case but I suspect it might be.

Yes I do add my bleach mostly in the evenings since I do use the spa at that time.

I do not shock at all.

I do keep open my spa cover for about 10 min.Maybe that is to short....

Also what happen winter time how long I should keep the spa uncover.

I hope 10 min is ok for winter time since dropping temperature it is going to use my heater.

What is proper prosiger to clean the internal filters?

Thanks again

Adam

[styro]

Look for Potassium peroxymonosulfate (also known as MPS or potassium monopersulfate).

You could also increase your filtration and ozonator run times.

Hi,

I Did purchase today product call Energize it is containing Potassium monopersulfate - 32%

From the label it's stated 125g per 1000 liters use for freshly filed spa and for regular daily treatment 30 g per 1000 l.

Which one apply to me since I want to use not on regular basis only when I have a problem.

My spa is 1280 liters(325 gal)

What do you recommend?

Thanks

[quantumchromodynamics]

Start with about 30 grams and see what happens. Note that MPS can register on the CC test unless you get a special interference remover. The MPS should be gone within about 24 hours. Therefore, you will have to ignore CC levels for about 24 hours. You should be able to tell if the chloramines go away by the smell.

Commencez avec environ 30 grammes et de voir ce qui se passe. Note que le potassium monopersulfate peuvent s'inscrire sur le test de chlore combiné à moins d'avoir un réactif spécial. monopersulfate de potassium devraient être allé au bout de 24 heures. Par conséquent, vous devez ignorer les niveaux de chlore combiné pendant environ 24 heures. Vous devriez être en mesure de dire si les chloramines sont partis par l'odeur .

[styro]

Start with about 30 grams and see what happens. Note that MPS can register on the CC test unless you get a special interference remover. The MPS should be gone within about 24 hours. Therefore, you will have to ignore CC levels for about 24 hours. You should be able to tell if the chloramines go away by the smell.

Commencez avec environ 30 grammes et de voir ce qui se passe. Note que le potassium monopersulfate peuvent s'inscrire sur le test de chlore combiné à moins d'avoir un réactif spécial. monopersulfate de potassium devraient être allé au bout de 24 heures. Par conséquent, vous devez ignorer les niveaux de chlore combiné pendant environ 24 heures. Vous devriez être en mesure de dire si les chloramines sont partis par l'odeur .

I did start 3 days ago with 60g off potassium monopersulfate.

At this moment before I add potassium my F.ch was 2.42 and T.ch 3.27

I also add like every day regular douse of chlorine.

I did measure my water after 12 hrs and my F.ch was 6.59 and T.ch 8.80

The difference was big 2.21

After 12 hours (total 24 hrs)from imputing 60g of potassium the F.ch 3.44 and T.ch 4.30

The difference only 0.86 (not bad ,but still out of range)

Yesterday I added extra 30g potassium monopersulfate.

Today after 24 hrs :F.ch 4.59 and T.ch 5.65

again the difference are larger 1.06

I don't know if I'm going in good direction?

Any help appreciate.

Adam

[waterbear]

Start with about 30 grams and see what happens. Note that MPS can register on the CC test unless you get a special interference remover. The MPS should be gone within about 24 hours. Therefore, you will have to ignore CC levels for about 24 hours. You should be able to tell if the chloramines go away by the smell.

Commencez avec environ 30 grammes et de voir ce qui se passe. Note que le potassium monopersulfate peuvent s'inscrire sur le test de chlore combiné à moins d'avoir un réactif spécial. monopersulfate de potassium devraient être allé au bout de 24 heures. Par conséquent, vous devez ignorer les niveaux de chlore combiné pendant environ 24 heures. Vous devriez être en mesure de dire si les chloramines sont partis par l'odeur .

I did start 3 days ago with 60g off potassium monopersulfate.

At this moment before I add potassium my F.ch was 2.42 and T.ch 3.27

I also add like every day regular douse of chlorine.

I did measure my water after 12 hrs and my F.ch was 6.59 and T.ch 8.80

The difference was big 2.21

After 12 hours (total 24 hrs)from imputing 60g of potassium the F.ch 3.44 and T.ch 4.30

The difference only 0.86 (not bad ,but still out of range)

Yesterday I added extra 30g potassium monopersulfate.

Today after 24 hrs :F.ch 4.59 and T.ch 5.65

again the difference are larger 1.06

I don't know if I'm going in good direction?

Any help appreciate.

Adam

Unless you are using a special reagent to remove the interference from the MPS you need to ignore CC readings when using MPS since it WILL test as CC. I have seen the interference last longer than 24 hours. Much depends on the organic load in the water at the time you add it.

[styro]

Start with about 30 grams and see what happens. Note that MPS can register on the CC test unless you get a special interference remover. The MPS should be gone within about 24 hours. Therefore, you will have to ignore CC levels for about 24 hours. You should be able to tell if the chloramines go away by the smell.

Commencez avec environ 30 grammes et de voir ce qui se passe. Note que le potassium monopersulfate peuvent s'inscrire sur le test de chlore combiné à moins d'avoir un réactif spécial. monopersulfate de potassium devraient être allé au bout de 24 heures. Par conséquent, vous devez ignorer les niveaux de chlore combiné pendant environ 24 heures. Vous devriez être en mesure de dire si les chloramines sont partis par l'odeur .

I did start 3 days ago with 60g off potassium monopersulfate.

At this moment before I add potassium my F.ch was 2.42 and T.ch 3.27

I also add like every day regular douse of chlorine.

I did measure my water after 12 hrs and my F.ch was 6.59 and T.ch 8.80

The difference was big 2.21

After 12 hours (total 24 hrs)from imputing 60g of potassium the F.ch 3.44 and T.ch 4.30

The difference only 0.86 (not bad ,but still out of range)

Yesterday I added extra 30g potassium monopersulfate.

Today after 24 hrs :F.ch 4.59 and T.ch 5.65

again the difference are larger 1.06

I don't know if I'm going in good direction?

Any help appreciate.

Adam

Unless you are using a special reagent to remove the interference from the MPS you need to ignore CC readings when using MPS since it WILL test as CC. I have seen the interference last longer than 24 hours. Much depends on the organic load in the water at the time you add it.

Ok,

I'm completely confuse and lost.

Can you please tell me should I add more mps(potassium monoper.........)without special regent or just wait few more days and check my f.ch and T.ch levels.(they should go back to normal within.........days)

I do not know if I have to stop or add more 30g of potassium every day?

[waterbear]

It is often impossible to completely eliminate CC in a hot tub using chlorine because of the large bather to water ratio. There are a LOT of organics in the small volume of water. The goal is to keep it below .5 ppm and this is often very difficult. A few things that will help are to shock with the cover off and the spa exposed to sunlight with the jets going and to keep it uncovered for several hours. Sunlight is one of the necessary ingredients to destroy CC.

The other way to go is to stop shocking with chlorine but to shock weekly with MPS. This will keep a reserve of MPS in the water to destroy organics before they form CC. However, MPS will test as CC so if you go this route just ignore CC readings as long as the water is clear and your FC is hoding at the proper level and there are no unwanted strong smells from the spa. I would still leave the spa uncovered when you shock. (This is where much people run into problems, they shock and then cover the spa half an hour later...the same effect is seen in pools that are kept covered, the formation of persistent CC that is difficult to destroy. It is also seen in indoor pools that get no exposure to sunlight. In these cases MPS is often the best way to go.

However, MPS is more expensive than chlorine and also many people do develop irritation from it after a while so it does have some other downsides besides interfering with test results.

Hope this helps clear up your confusion. Choose either chlorine shocking (done properly) or MPS shocking (and ignoring CC readings). If you go the MPS route then shocking MUST become part of your weekly spa maintenance program and not "as needed when CC is higher than .5 ppm" as it is with chlorine shocking.

[quantumchromodynamics]

You could increase your ozonator run time.

You could get the Taylor K-2042 Monopersulfate test.

Instructions

I think that the Taylor reagent should work with your kit. Do you have the Color Q Pro 7? I think that LaMotte has an MPS test reagent also.

I'm not so sure that your test is quite as precise as is being reported. The numbers seem too exact to be accurate. You should get the FAS-DPD chlorine test.

You mentioned that the water had a chloramine smell. Does the water still have a chloramine smell?

[styro]

Thanks for all inputs,

Waterbear now all is more clear.

Quantumchromodynamics my ColorQ pro7 it is very accurate and has no Mps test regents.

Ozonator is set to do the work 4x 2hrs/day.

Water still had some chloramine smell but not that strong.

I guess my problem is also because I'm closing my cover after half an hrs after addition of chemicals.

Normal prossegger is addition of chemicals water aeration and cover closed after 10-15 min.

How about winter in case of CC High?

In my case when the CC is high I should keep my spa open xposed to sunlight for few hrs like Waterbear mention.(no problem is summer)

I will try this tomorrow.

Thanks

Adam

[waterbear]

Thanks for all inputs,

Waterbear now all is more clear.

Quantumchromodynamics my ColorQ pro7 it is very accurate and has no Mps test regents.

No, it is not. I have spoken to LaMotte techs about the ColorQ to see if we wanted to carry it in addtion to our other test kits, both LaMotte and Taylor (where I used to work used the Waterlink and I have been certified by LaMotte in their testing system) and the tech said that it does an amazing job FOR THE MONEY. Consider that the Waterlink Express retail to stores for over $1200 and is one of their less expensive "professional" meters. Just because it gives you a readout with a lot of decimal places does not mean it really has that kind of precision. There are also limitations in LaMotte's chemistry itself. (where they have turned titrations into colormetric tests).

LaMotte does make a stand alone Cl/MPS/pH test kit #3360 that uses octa slide comparators so it is in their "professional" line but you are correct that they do not supply an MPS reagent for the colorQ. Taylor does have an MPS interference reagent available for the K2000 series of test kits.

Ozonator is set to do the work 4x 2hrs/day.

If you have any ozone residual in the water this will also test as CC. Well designed systems are not supposed to have any residual ozone by they seem to not really exist anymore because of the cost.

Water still had some chloramine smell but not that strong.

I guess my problem is also because I'm closing my cover after half an hrs after addition of chemicals.

Yep, usually the cause!

Normal prossegger is addition of chemicals water aeration and cover closed after 10-15 min.

How about winter in case of CC High?

In my case when the CC is high I should keep my spa open xposed to sunlight for few hrs like Waterbear mention.(no problem is summer)

Yes, if you have a problem with persistent CC. The disinfection byproducts (nasty and smelly CCs) need to gas off. You won't lose as much heat as you think you will but you will lose some.

I will try this tomorrow.

Thanks

Adam

It can sometimes take more than one shock cycle to get rid of some of the nastier and smellier disinfection byproducts.

[footie]

I would still leave the spa uncovered when you shock. (This is where much people run into problems, they shock and then cover the spa half an hour later...the same effect is seen in pools that are kept covered, the formation of persistent CC that is difficult to destroy. It is also seen in indoor pools that get no exposure to sunlight. In these cases MPS is often the best way to go.

However, MPS is more expensive than chlorine and also many people do develop irritation from it after a while so it does have some other downsides besides interfering with test results..

As someone with an indoor pool I can't say I have had too much trouble controlling the chemicals in the water. I run it at 1.5 ppm mainly because it's only used by the family and only twice weekly, I only shock it twice yearly and you are right about removing the cover as I keep mine off for a full day each time but drain off about 400 litres of pool water bi-monthly which is replaced by tap water. I only use Sodium Hypochlorite, baking soda and dry acid to control the water yet do all the other tests as well.

I'm hoping the tub will be as easily controlled but because of the high people to water ratio I am sure this is not going to be the case.