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Anonymous Poster

Bleach versus Chlorine

08/30/2007 9:03 AM

My wife put bleach iin the pool thinking it was the same as chlorine. Can someone explain the difference to me so i can explain it to her? Thank you.

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Guru
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#1

Re: bleach?

08/30/2007 9:14 AM

Sodum or calcium hypochlorite are both solids: they release free chlorine when dissolved and are a safer option than having canisters of chlorine gas hanging around.

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#2

Re: Bleach versus Chlorine

08/30/2007 2:44 PM

Household bleach is typically about 10% calcium hypo-chlorite. It is an excellent 'germ and algae killer' However, it does add calcium (hardness) to the pool water and can cause scale deposits to form if the hardness gets too high. Also, it is not resistant to sunlight degradation. However, it IS cheap and effective for 'shocking' the pool.

I feel certain when you use 'chlorine' you are referring to one of the dry 'chlorine tablets/granules/powders made for ease of use in domestic swimming pools. No homeowner would have a liquid chlorine cylinder feeding his pool chlorinator.

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#3
In reply to #2

Re: Bleach versus Chlorine

08/30/2007 4:17 PM

Actually, (in the US) liquid household "bleach" is typically between 5 and 6.5% sodium hypochlorite. (NaOCl). As Mr. Bowers states, this product does react and photodegrade fairly rapidly, and does not provide long term "residual chlorine" for sanitizing.

Calcium hypochlorite is usually available in granular or tablet form. Often used to "shock" the pool. It is less expensive that some other forms of chlorination, but is not as stable, has a very high pH, and can combust violently if it becomes contaminated with some substances. (I recall an old formula consisting of brake fluid and "HTH" being used back in the 70's for nefarious purposes).

Chlorine in cylinders is a gas (as opposed to a liquid). More than 30 years ago, I worked in a summer camp where the pool was chlorinated via gas cylinders. Let me tell you, it was no fun changing out the cylinders, even with a gas mask. You would check for chlorine leaks with an open bottle of ammonium hydroxide solution. IF the chlorine was leaking, it would instantly react with the "ammonia" vapors, and form dense white "smoke" (actually chloramine). Kind of neat to see, but definitely not something you wanted to breathe in.

The Solid form of pool chlorination, Trichlor (short for Trichloro-s-triazinetrione) has a stabilizer added (cyanuric acid ), allowing it to be effective in a slow-dissolving tablet. This formulation is typically quite acidic, and therefore corrosive to metals.

The Granular form of pool chlorination, Dichlor (short for Sodium Dichloro -s-triazinetrione). Nearly neutral pH, but expensive due to the low percentage of "available chlorine".

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Anonymous Poster
#5
In reply to #3

Re: Bleach versus Chlorine

08/31/2007 12:13 AM

A question comes up relative to the free chlorine content of bleach. It would seem that the available chlorine for disinfection is only the chlorine content of the bleach as a fraction of the NaOCl, yet some sources call theOCl- portion the available chlorine. Why?

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#11
In reply to #5

Re: Bleach versus Chlorine

08/31/2007 9:43 AM

When NaOCl or Ca(OCL)2 is added to water, they hydrolyze into sodium and calcium cations and OCl-. This is what is responsible for the most effective disinfection.

If you add table salt to water, Na+ and Cl- ions are formed. Cl- does not have the disinfecting power or OCl-.

OCl- can react with ammonia/amines in the water to form chloraramines, which has much less disinfection power, and is responsible for the strong "chlorine" smell people complain about.

OCl- is practically odorless at low ppm levels while chloramines have a strong smell and are irritating. In heavily used pools this is often a problem. When people complain about a pool having "too much chlorine", is because of chloramines, not OCl-. These pools actually need more OCl-, which will destroy the chloramines.

Free chlorine tests only measure OCl-, while total chlorine tests measures OCl- + chloramines.

Tad

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Anonymous Poster
#13
In reply to #11

Re: Bleach versus Chlorine

08/31/2007 2:48 PM

When chlorine gas is added to water, does the gas hydrolyze into OCl- ?

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#14
In reply to #13

Re: Bleach versus Chlorine

08/31/2007 3:54 PM

Yes:

Cl2 + H2O -> H+(aq) + Cl-(aq) + HClO(aq)

Actually what I stated before is a bit simplistic. HClO ->H+ + OCl- is actually an equilibrium, depending on pH. At a pH of 7.6, their concentrations are equal. I believe that a free chlorine test measures both HOCl and OCl- as well as other oxidizing species, but not chloramines.


Tad

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#17
In reply to #3

Re: Bleach versus Chlorine

09/01/2007 8:56 PM

JMan, actually, chlorine for most uses is supplied as a liquid under prtessure.

Cylinders are: #761 contain 2,000 #; #054 contain 150 # and #007 contains 7 pounds. The cylinders contain liquid Cl2 at 85.3 pressure at 70 F. Cl2 gas had a density of 5.4 #/cu ft. The liquid Cl2 is a clear, amber liquid with a density ~ 1,500 g per liter. As little as 2.5 mg per liter in air (0.085 % by volume) can cause death in minutes. Phosgene is even more insidious. A few breathes of phosgene does not seem to affect a person, but the gas is hydrolyzed in the lungs to hydrochloric acid, which slowly eats the lung tissue and death results.

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#18
In reply to #17

Re: Bleach versus Chlorine

09/01/2007 10:10 PM

I believe phosgene was used as one of the poisonous gases in WWI. I was once told that phosgene could form under proper conditions if carbon tetrachloride was used on a hot fire and that use of CCl4 was therefore discontinued in fir extiguishers.

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#19
In reply to #17

Re: Bleach versus Chlorine

09/03/2007 3:00 AM

Cardio-2,

I am well aware that chlorine in a cylinder is in a liquid-gas equilibrium, but that is true of a quite a number of compressed gases. Initially the cylinder is mostly filled with liquid, and gas fills the headspace above the liquid. As gas is dispensed from the cylinder, enough liquid evaporates to replace it, keeping the headspace pressure in the cylinder constant .

That being said, in fact, the actual chlorine is dispensed from the cylinder as a gas. Chlorine does not exist as a liquid a "normal" temperature and pressure. At atmospheric pressure, its boiling point is -30°F. At higher temperatures than that, it exists only as a gas...

==============================================================================

Excluding cryogenic gasses, which are really a class to themselves, there are three major classes of compressed gases normally stored in cylinders: liquefied, non-liquefied and dissolved gases.

  • Liquefied gases can exist as liquids at normal temperatures, when stored under pressure inside cylinders. Carbon dioxide, chlorine, anhydrous ammonia, propane, butane, nitrous oxide and hydrochlorofluorocarbon refrigerants are common examples.
  • Non-liquefied gases (aka permanent gases) do not become liquid when they are compressed at normal temperatures. Common examples of these are oxygen, nitrogen, helium and argon.
  • Dissolved gases – The most common example would be acetylene. Acetylene in solution is stable. However, when not in solution, acetylene can explode when compressed beyond beyond 1 standard atmosphere (101.325 kPa). Cylinders used to store acetylene are fully packed with an inert mass of uniformly porous filler, composed of calcium silicate (often including asbestos). The filler is then saturated with a suitable solvent, typically acetone. When acetylene gas is finally added to the cylinder, the gas dissolves in the acetone.

===============================================================================

By the way, I was referring to chloramine (NH2Cl), not phosgene.

Cl2 + NH3 => NH2Cl + HCl.

In order for phosgene (COCl2) to form, free carbon must be available.

While phosgene is indeed nasty, chloramine is no walk in the park. Just try mixing some household bleach with a little ammonia and see what happens.

(Just kidding… Don't try this at home!!!)

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#21
In reply to #2

Re: Bleach versus Chlorine

05/17/2008 11:15 AM

I have the same question because I am not sure the origninal question has been answered. You appear to be asuming the person is talking about tablets/granules/powders. But I believe the original writer is talking about the difference between Household bleach and (liquid Chlorine Bleach) we buy at the pool store. I usually fill two (2 1/2) gallon jugs at the pool store every two weeks. Is there any difference in these to liquid bleaches. I have had some pool store owners tell me Pool Bleach is stronger.

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#23
In reply to #21

Re: Bleach versus Chlorine

05/17/2008 11:36 AM

Household bleach is about 5% sodium hypochlorite. I believe the liquid sold at pool stores is 10-12% sodium hypochlorite. Check the label, the concentration is shown.

Tad

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#24
In reply to #23

Re: Bleach versus Chlorine

05/17/2008 3:50 PM

Thanks. Do you know if the concentration is measurable?

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#25
In reply to #24

Re: Bleach versus Chlorine

05/18/2008 4:48 PM

Sorry, I am not sure what you are asking. Do you mean a chemical analysis?

Tada

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#26
In reply to #25

Re: Bleach versus Chlorine

05/19/2008 1:59 AM

I am just wondering how one knows if the bleach we are buying is of a particular concentration. How do I not know the supplier is not watering down the bleach? Would may think they are buying 2 1/2 gallons of 12% concentration when in fact we are getting half water and half bleach.

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#27
In reply to #26

Re: Bleach versus Chlorine

05/19/2008 8:30 AM

Well, you could analyze the bleach, but that would cost as much, if not more than the bleach itself. I would think that see/smell the difference.

A crude test would be to accurately weigh the bottles. Household bleach should be 5% higher in weight than plain water, the pool stuff 10-12% higher.

Sometimes you have to have a little faith.

Tad

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#22
In reply to #2

Re: Bleach versus Chlorine

05/17/2008 11:23 AM

I have the same question because I am not sure the origninal question has been answere. You appear to be asuming the person is talking about tablets/granules/powders. But I and I believe the original writer is talking about the difference between Household bleach and (liquid Chlorine Bleach) we buy at the pool store. I usually fill two (2 1/2) gallon jugs at the pool store every two weeks. Is there any difference in these to liquid bleach. I had some pool store owners tell me Pool Bleach is stronger.

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Anonymous Poster
#4

Re: Bleach versus Chlorine

08/30/2007 5:55 PM

Thank you for the answeres. It sounds as though it's not too bad then. She was really worried. I told her I would find some info. Thank again.

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#6
In reply to #4

Re: Bleach versus Chlorine

08/31/2007 2:28 AM

Bleach may also contain fabric brightening and/ or softening agents and sometimes mild detergents.

As long as you use it in combination with solid chlorine, you should be fine.

It worked for me in the past.

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#20
In reply to #6

Re: Bleach versus Chlorine

09/10/2007 1:57 PM

Is that why you look like that?

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#7

Re: Bleach versus Chlorine

08/31/2007 9:07 AM

To me the difference would be the cost. Household bleach costs more than chlorine for pool use, although they both cost about 1.25 per gallon, because it takes more to accomplish the same thing.

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#8

Re: Bleach versus Chlorine

08/31/2007 9:30 AM

hi

bleach is NaOCl, sodium hypochlorite, which evolves chlorine on contact with water....

and chlorine is .... well chlorine ofcourse....

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#9

Re: Bleach versus Chlorine

08/31/2007 9:36 AM

The chemical that chlorinates and disinfects the water is hypochlorite. It is the same chlorine. It just released differently with the tablets.

So you need to appologize to your wife.

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Anonymous Poster
#12
In reply to #9

Re: Bleach versus Chlorine

08/31/2007 1:59 PM

Apologize for what? I don't believe that I stated an accusation against her. I told her I would look into it because she had concerns for our kids going in the pool if it was a bad thing. So apology is required or necessary.

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Anonymous Poster
#10

Re: Bleach versus Chlorine

08/31/2007 9:39 AM

Sir: Its the Oxygen that does the Bleaching

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#15

Re: Bleach versus Chlorine

09/01/2007 7:56 AM

I build inexpensive sodium hypochlorite "bleach" production systems for use in a village setting for safe drinking water development. Using about 1 pound of table salt in 5 gallons of water will produce enough chlorine to disenfect 25000 gallons of water.

Very economical salt, water and DC current. Easy to always have a fresh supply of bleach.

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#16

Re: Bleach versus Chlorine

09/01/2007 8:09 AM

We added bleach from a bottle one year to our pool and had we all got swimmers ear.

Never used it again and not porblems with swimmers ear either.

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Anonymous Poster
#28

Re: Bleach versus Chlorine

04/25/2009 7:33 PM

I have been wondering this for quite a while now - especially after checking the labels & finding that BOTH contain SODIUM HYPOCHLORITE. (and only the pool shock listed the percent - 10%)

So then finally sat down to investigate

Here is the clearest answer I've found and my pool guy friend agreed. And oh! btw he's also told me the main ingredient in those "pool warming fish" is rubbing alcohol, and a heck of a lot cheaper at the dollar store. $13.00 per omg.

Here's what I found re: Bleach versus Chlorine

Best Answer - Chosen by Asker

Pool shock is calcium hypochlorite. Liquid bleach is sodium hypochlorite. Liquid pool shock is sodium hypochlorite.

Yes, they are all basically the exact same things, the only difference is which metal they are bonded with for delivery and stability.

Calcium hypochlorite is the granulated form of pool chlorine. It is useful if you have an in ground plaster/concrete/gunite/tile pool as it supplies calcium to the water to help maintain hardness.

Sodium hypochlorite is liquid form. This is useful to use if you have a vinyl lined pool since you don't need to maintain elevated calcium hardness in these types of pools.

Household bleach (non scented) is 6% sodium hypochlorite by solution. Liquid pool chlorine is 10%-12% sodium hypochlorite by solution. Granulated chlorine is 65% calcium hypochlorite.

10oz of granulated chlorine = 1/2 gallon of liquid pool chlorine = 1 gallon of household bleach. These measurements will raise the chlorine level by 5ppm in 10,000 gallons of water. Source(s): Registered CPO (Certified Pool Operator) with the National Swimming Pool Federation http://www.nspf.com/ and maintaining public access swimming pools for many years now.

*link to this is - http://answers.yahoo.com/question/index?qid=20070608193348AActO7L

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#29
In reply to #28

Re: Bleach versus Chlorine

04/26/2009 11:15 AM

Rubbing alcohol (isopropyl alcohol) is the main ingredient in the fishes, but it is not the active ingredient. Although it is proprietary, the active ingredient is likely to be Polyoxyethylene (2) lauryl ether or a related compound. It forms a thin polymer film on the surface, reducing evaporation

Less evaporation, less heat loss.

Although vinyl pools do not require as high a calcium level as concrete pools, 80-150 ppm calcium is desirable to provide pH buffering and to avoid corrosion.

Tad

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#30
In reply to #28

Re: Bleach versus Chlorine

07/30/2010 1:13 PM

In numerous attempts to solve my recurring algae problem I found this site. I have shocked, algae-cided, shocked again, vacuumed to waste and started all over again. While the pool is 90% improved, it still gets algae in it although the chlorine levels show to be very high while shocking it. (as measured on a dip-stick). I have an actual liquid tester kit coming. I began this summer by changing the sand. I have a 30ft round pool which is approx 48-52" deep. I treat based on about 21K gallons.

The algae in the pool never seems to actually die. There are always green algae hovering on the bottom within hours of vacuuming. I'm not sure why the algae isn't killed off using the shock and algaecide. I've used the strongest products I can find.

I read that using standard bleach may resolve my issue because it will only input Chlorine as opposed to powdered shock which has stabilizers in it that apparently can build up making the chlorine ineffective. I continually vacuum to waste when I see algae so the pool water gets (in effect) drained and refilled to a certain degree. 3-6 inches x 30 ft round every time I need to vacuum to waste depending on how quickly I can vacuum.

Prior to reading this forum, I had resolved myself to taking the top off the sand filter and pouring algaecide and/or bleach into the filter tank in the evening, letting it sit and hopefully destroying any algae that may be residing in the filter tank. Is that a possible solution or would I be wasting my time?

The weather here has been hot / humid and the pool has not gotten much use. When it's not hot/humid - it rains. (northeastern Illinois).

I also thought perhaps I could design some type of water stimulator to get the water moving about the pool a tad more vigorously. A small rotating sprinkler attached to a hose that would attach to the inlet of the pool. The sprinkler would sit on the pool floor and send water out from there to get it moving. I thought that this might improve circulation which would in turn help to distribute chemicals that I've added.

Is it a delusional thought that algae has built up inside my filter tank?

In this ecomony, I'm having a hard time affording all of the chemicals to keep the pool clean. Any help anyone can offer would be GREATLY appreciated.

thanks,

-susie

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#31
In reply to #30

Re: Bleach versus Chlorine

07/30/2010 1:51 PM

Hi Susie,

Welcome to CR4.

I have never found the standard algaecide that sells in most stores to have any effect at all. A copper based algaecide (it will contain copper sulfate) seems to do the trick for me. Pool stores will sometimes steer you away from this, as it can stain the lining if not used properly. Just use the minimum amount indicated, sprinkle it around the pool away from the wall so it is diluted well. I have a vinyl lined pool, and never had a problem. It generally solves my algae problem for the season.

You may also have a problem with fine algae passing through your filter. I recommend a product called "Sparkle Up" by BioGaurd. It is a filter aid which will remove very fine particles. I have had good luck getting rid of a green tint in the pool which would not go away even after 3 days of constant filtering. Sparkle Up gets rid of it over night.

If you are shocking with a calcium hypochlorite powder, it contains no stabilizers, so it will not be a problem. Household bleach is also fine, although it may raise the pH. I do not recommend using powders that use "dichloro-" or "trichlo-" chlorine compounds for shock (they are fine for everyday use). These do have stabilizers, and can cause a the dreaded "chlorine lock". I used the stabilized chlorine one year for shock, and all was fine during the season. However, the next year when I opened the pool, it took 50 lbs. of chlorine before I got any active chlorine reading! Never again.

Good luck!

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#32
In reply to #31

Re: Bleach versus Chlorine

07/30/2010 2:34 PM

Thank you for responding. I had considered the copper based algaecide but read the warning to avoid it if I had a vinyl liner pool. I asked one pool guy at a local store about it and he reported that NO algaecide would kill algae and proceeded to sell me 3 bags of $6 per bag shock. I guess I should learn to trust my instincts.

Today is overcast so I decided to add some super shock to the pool since I doubted anyone would be swimming. It seems that it may have killed the algae. I can't see any green spots, but I do see some white sediment on the bottom. I believe that might be dead algae? The main ingredient is 73% calcium hypochlorite. other ingred = 27%. I just threw it in around the pool edges and then kind of stirred it in with my pool brush.

do you have any thoughts on my adding stuff to the actual filter tank and let it sit overnight?

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#34
In reply to #32

Re: Bleach versus Chlorine

07/30/2010 3:22 PM

I heard the same warning about vinyl pool staining. However, I used to have algae problems every year, and the standard algaecide did nothing. Yellow, green and black algae. Even with good chlorine levels, I had to sweep the pool every day, and still had algae. I used the copper based algaecide, and it kills everything. Even with chlorine levels at zero, little or no algae is seen. I can't tell you how much easier the pool is to maintain after using the copper algaecide.

Just add it slowly all around the pool, and I've never had a staining problem.

Not knowing the construction of your filter, too high a chlorine level may be damaging. Organic material in your filter will likely decompose the chlorine anyway. If the algae is being killed in the water, it will be killed in the filter as the water flows through.

The gray stuff is dead algae. Congrats! Unfortunately, the algae may only be killed by the high chlorine levels, and may come back.

I don't know about sand filters (mine is DE), but channeling can occur, where there is an open path channel through the sand, so that the water only is partially going through the sand. Since you said you replaced the sand, you may want to be sure that it is evenly dispersed in the filter.

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#35
In reply to #34

Re: Bleach versus Chlorine

07/30/2010 3:51 PM

I just spoke to a gal at the pool store who said she things what I have is similar to mustard algae but called it small spore green algae. Her suggestion was to supershock the pool and then add 2 qts of thier algaecide. I asked her how much the algaecide was and she reported it was $29 per quart. I just can't afford that. I can buy the copper based algaecide at the big box pool store for around $10 qt. I don't know the amounts of copper in it. Do you have a suggestion?

another site I looked at said I may have to add 50 lbs of shock to kill the algae.

I live in the middle of a farm field. I've used the Phosfree and that didn't help.

this is not only frustrating - it's becoming VERY expensive.

I need some really good advice and LOTS of moral support. You've at least got me thinking I may be able to combat this without a 2nd mortgage. :-)

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#38
In reply to #35

Re: Bleach versus Chlorine

07/30/2010 4:32 PM

Have faith! This may make you feel better. The description of this copper based algaecide says it's specifically for vinyl pools, but will work in others! This is a chelated copper algaecide, which is supposed to be safer as far as staining. I've used both in the past, but the plain old copper sulfate based stuff has never given me a problem either.

Copper content can be written in different ways, so I would just follow the directions. Dilute it down in a bucket of water before you add to the pool if it makes you feel better. If you are still nervous, add half the amount they recommend, and work up to the dose that is effective.

$10/qt is a good price, I have paid $15 in the past. I'm a chemist, so now I make my own for about $1/qt.

Go for the copper!

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#33
In reply to #31

Re: Bleach versus Chlorine

07/30/2010 2:39 PM

could yo explain to me what chlorine lock is? I've heard the term but don't know what it means. someone said that I'd need to add non-chlorine shock in order to break the lock.

I wish I'd know the other day what you just told me about the different types of shock. I would have purchased more of the calcium type.

-susie

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#36
In reply to #33

Re: Bleach versus Chlorine

07/30/2010 4:00 PM

UV light from the sun decomposes "free" chlorine. To reduce this effect, stabilizer (cyuranic acid) can be added, or stabilized chlorine (dichloro- or trichloro-) can be used. The effect is that a loose chemical bond is formed with "free" chlorine. This prevents UV decomposition, but still allows the chlorine to act as free chlorine and disinfect. However, the efficiency of the chlorine is slightly reduced, due to the bond with the stabilizer.

Eventually the stabilized chlorine breaks down. The chlorine leaves the water through various mechanisms, but the stabilizer stays behind. Over time, the concentration of stabilizer builds up.

After a while, the pool has no chlorine, but lots of stabilizer. If you add stabilized chlorine at this point, your problem will get worse and worse. If you add the calcium hypochlorite chlorine, the stabilizer will attach to the chlorine as intended. However, if stabilizer levels are high, the stabilizer may bond with the chlorine in such a way that it is not seen as "free" chlorine until a huge amount of chlorine is added.

Another form of chlorine lock is when levels of compounds called amines (humans release a lot of amines/ammonia) build up in the water. These compounds can also attach to chlorine (to form chloramines), but so strongly that the chlorine has little disinfection properties. When this occurs, you will see a high level of "total chlorine" with little "free chlorine".

"Shocking" breaks this bond, and releases the chlorine so that it is "free".

Interestingly, the chloramines have a strong smell, are very irritating to eyes and are a common problem in heavily used pools. Have you ever had someone say that they hate commercial pools "because they use too much chlorine"? The opposite is true. The strong chlorine smell and irritation are caused by chloramines. The problem is eliminated by shocking the pool with a high level of chlorine.

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#37
In reply to #36

Re: Bleach versus Chlorine

07/30/2010 4:25 PM

Do you have a recommendation for the level of copper in a copper based algaecide? I do have well water and we do have lots of iron in our water - however - we filter most of it out - even the water we use to fill the pool. If we didn't - we'd have orange pool water.

I found some 7% copper based algaecide for around $12 on Ebay. Is there something else I should be looking for besides the copper content? How much (qts?) would I need for a 21,000 gal pool?

Shock first? with calcium based pool shock?

thanks,

-susie

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Power-User

Join Date: Dec 2006
Posts: 443
Good Answers: 31
#39
In reply to #37

Re: Bleach versus Chlorine

07/30/2010 4:49 PM

I've got well water too, but not much iron.

I won't go into technical details, but the label just saying 7% really is ambiguous. To really know the copper content, the concentration has to be followed by "as". As an example, the stuff I use is 11.8% as copper sulfate pentahydrate, but 3% as elemental copper.

The amount depends on copper content. I would just follow the directions. 1 have about 25,000 gallons, and I use 1 qt. This is less than half of the recommended dose for severe algae treatment. Looking at other brands, I see they recommend much lower amounts, so I would just go with the directions.

Shocking is not necessary. It sounds like you have shocked the hell out of it already!

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Member

Join Date: Jul 2010
Posts: 6
#40
In reply to #39

Re: Bleach versus Chlorine

07/30/2010 6:29 PM

I'll look for that wording on the label when I go hunting for the algaecide. You're certainly right about shocking. Not knowing which type of copper content I'm looking for, I'll see if I can find something that reads in a similar fashion.

I used to like the color green................

-susie

have a great weekend and thanks for all your help..

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