Is Bleach Just Dichlor Without Cya

[hrustar]

Just wondering if bleach is the same as dichlor sans the cya? I ask because everytime I mention using bleach to someone, they look at me as though I said I filling my spa with acid. I wonder is it's the word bleach that throws them off, since, to my understanding, bleach is just liquid chlorine?

[BigDfromTN]

Just wondering if bleach is the same as dichlor sans the cya? I ask because everytime I mention using bleach to someone, they look at me as though I said I filling my spa with acid. I wonder is it's the word bleach that throws them off, since, to my understanding, bleach is just liquid chlorine?

As I understand it you are correct!

Some people get hung up on having to buy what the "pool/spa Store Guys" sell them. This only serves to advance their cause and not make your wallet and tub in any better shape.

Im sure Nitro and/or ChemGeek will be along and set us both straight if this is not the case. (and please do so guys.)

[OttawaGreg]

Bleach (Clorox 6%) is sodium hypochlorite. So I guess, yes, it is simply liquid chlorine. (saline based?)

The expensive stuff in powder is Lithium hypochlorite. My neighbor with a pool uses calcium hypochlorite.

We should just say "I use liquid chlorine" as my sanitizer to people instead of "Bleach" and get the raised eyebrows...

Greg

[Dr. Spa]

Chlorine is a gas. dichloc, bleach, trichlor, Lithium hypochlorite, Calcium Hypochlorite etc are simply different products that contain chlorine used to deliver it in a solid form.

[OttawaGreg]

Did a quick search and came up with this article. Worth the read..

>excerpt>

Chlorine is chlorine, so the chlorine in bleach is the same as the chlorine in drinking water and in a swimming pool. In fact, you can use chlorine bleach to treat a swimming pool or to treat drinking water. A gallon of bleach provides 1 part per million (PPM) of chlorine to 60,000 gallons (about 250,000 liters) of water. Typically, a pool is treated at a rate of 3 PPM, and drinking water is treated at anywhere from 0.2 PPM to 3 PPM depending on the level of contamination and the contact time.

http://science.howstuffworks.com/question189.htm

[hrustar]

Did a quick search and came up with this article. Worth the read..

>excerpt>

Chlorine is chlorine, so the chlorine in bleach is the same as the chlorine in drinking water and in a swimming pool. In fact, you can use chlorine bleach to treat a swimming pool or to treat drinking water. A gallon of bleach provides 1 part per million (PPM) of chlorine to 60,000 gallons (about 250,000 liters) of water. Typically, a pool is treated at a rate of 3 PPM, and drinking water is treated at anywhere from 0.2 PPM to 3 PPM depending on the level of contamination and the contact time.

http://science.howstuffworks.com/question189.htm

Nice article find. Thanks.

[chem geek]

Yes, essentially bleach is just like Dichlor without the CYA except for the pH differences. When any source of chlorine is added to water, it will form hypochlorous acid (the active disinfecting form of chlorine), hypochlorite ion, and chlorine bound to CYA if CYA is either already present or being added in some way. The only differences between the different types of chlorine are in their initial physical characteristics (i.e. some are powder, some are liquid, some are in compressed pucks), in their concentrations, in what else they add to the water besides chlorine, and in their effect on pH.

Some people argue that the more concentrated forms of chlorine must be better because they are more concentrated. This is complete baloney. It just means you need to buy less by weight of such more concentrated products, but their price usually more than makes up for this difference. As an extreme example, lithium hypochlorite is essentially identical to bleach in terms of what it adds to the water since lithium and sodium ions are for all practical purposes the same in their completely innocuous (non-reacting) effect in the water and both products add an identical amount (per FC) of sodium chloride salt. Lithium hypochlorite is 35% Available Chlorine which means that it has 35% of the amount of chlorine potency of the same weight of chlorine gas. 6% bleach has 5.7% Available Chlorine so at first appears to be much weaker, but it is SO much cheaper by weight. Lithium hypochlorite costs around $6 per pound while bleach costs around 20 cents per pound. After accounting for lithium hypochlorite's higher concentration, the lithium hypochlorite is about 5 times as expensive as bleach for the same Free Chlorine (FC) amount. One can go through a similar analysis with Trichlor pucks which are 90% Available Chlorine and come to a similar conclusion that they aren't as inexpensive as they first seem, especially when taking into account the extra pH/TA adjustment chemicals needed when using Trichlor.

As for what "extra" gets added from different chlorine sources, the following are chemical rules of fact that are independent of concentration of product or of pool/spa size:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.

For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.

For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.

For all sources of chlorine, for every 10 ppm FC one gets 8 ppm salt as the chlorine gets used up and converted to chloride. For bleach, chlorinating liquid and lithium hypochlorite, one gets an additional 8 ppm salt upon addition.

The chemical process of chlorine getting used up is an acidic process so the net pH effect from different chlorine sources is that Trichlor is very acidic, Dichlor is acidic, while the hypochlorite sources of chlorine (bleach, chlorinating liquid, lithium hypochlorite, Cal-Hypo) are all close to pH neutral when accounting for chlorine consumption/usage.

Richard

[chem geek]

http://science.howstuffworks.com/question189.htm

One thing in that article isn't correct. It says the following:

When chlorine reacts with water, it produces hydrochloric acid and atomic oxygen. The oxygen reacts easily with the chromophores to eliminate the portion of its structure that causes the color.

Chlorine added to water produces hypochlorous acid, not hydrochloric acid (unless chlorine gas is being added, but even then the hydrochloric acid just lowers the pH which is then adjusted separately) and it does not produce atomic oxygen. Hypochlorous acid is a (selectively) strong oxidizer and reacts directly with the chromophores breaking them up so that they no longer absorb light and show color.