PDA

View Full Version : Chlorine %?



stlbill
04-16-2012, 08:02 PM
Hi folks:

What exactly does the sodium-hypo percentage mean? More targeted questions...

1. If a gallon of bleach is 6% what is the other 94% of the volume? Water?
2. Does 2 gallons of 6% provide the same chlorine as 1 gallon of 12%?

I think I know the answers to these questions. A couple of years ago I tried the BBB method using bleach from the grocery store. I dumped gallon after gallon in my pool with no increase in free chlorine. Using 12.5% liquid chlorine from the pool store I get the increase I expect much easier.

And something else is driving me nuts...

1. I can buy 3" pucks anywhere and have them shipped to me. No such luck with bleach. I have to buy it locally. What is the big problem with selling bleach on eBay and Amazon, for example? I have only found In The Swim will sell it in huge quantities... Quantitites that would go bad before I could ever use it all.
2. The concerning factor is that bleach seems to be more expensive than it used to be. It used to be a cheap secret to pool maintenance, but at over $4 a gallon for 6% generic at Wal-Mart I don't know if it is practicaly any more. I'm still waiting for the 12.5% price at the pool store to know for sure this season.

Sorry for the rant, poor grammar, etc. It usually isn't my style. I 've started composing a message like this a dozen times and never seem to have time to finish it. I always feel silly asking this and figure I am going to find the answers online elsewhere.

Thanks in advance!

lstinthot
04-16-2012, 08:29 PM
One gallon 12.5% chlorine is essentially the same as 2 gallons of 6% bleach. I believe some one on here once mentioned you may want to stay away from the generic bleach at Wal-mart. To many unknowns in the bleach, may not even be 6%. The 12.5% bleach will break down faster and will not stay true 12.5% as long as 6% stays 6%.

I have had pretty good luck with 12.5% pool shock from BJ's. Its a local big box store here. Like a Sams club or Costco. I am about to take on my neighbors pool with the stuff. Their pool is very very green almost black. They just opened it for the summer and said they spend $1000 opening it each year then have to shock it all summer to just keep it somewhat clear.

Shipping is cost prohibitive for bleach over the internet. Too bulky.

I switched last year and my brother switched end of last season, we are both believers now.

sunlove
04-16-2012, 08:44 PM
I am pretty new here myself, but yes you are right about the bleach. 6% is chlorine and the rest is water. Or at least that is what you hope for.


$4 a gallon for 6% generic at Wal-Mart

Holy smokes, where do you live? I can get generic 6% bleach for $1.50-1.75 at the grocery store or walmart or dollar store. Even Clorox doesn't cost but $2.50. But where I live the pool store is asking $7.99 for 12% chlorine! So you can see what I choose to do. I guess it just depends on your pool store prices...it may be cheaper for you to get it from them. :)

aylad
04-17-2012, 05:59 PM
Just to add a comment--the generic bleach from WalMart is fine, in fact it's actually better than the Clorox and other name brand bleaches, because of all the "extra" stuff they're adding to it. I use only the generic WalMart bleach in my pool.

Watermom
04-17-2012, 06:07 PM
I use only the generic WalMart bleach in my pool.

Me, too!

stlbill
04-17-2012, 10:55 PM
Hi gang:

6% generic bleach is $0.016/ounch at Wal-Mart here in St. Louis. I was doubling the price for 6% because I always seem to need double the amount talked about on these forums compared to 12.5% from the pool store.

So, in every gallon of 6% bleach there is 120 ounces of water. What do you guys think the quality of that water is? What do you think the total disolved solids and calcium hardness is like?

The reason I ask about the water in bleach is to promote bleach use for people trying to lower the parameters you can only lower by adding good water such as CH (excluding rare high pH method), CYA and TDS.

I'll leave you with one more thought...

Shouldn't we be able to calculate define units of hydrochloric acid required to offset a given amount of bleach? Not talking about other things that would make your pH change - just the bleach - you should be able to say for every gallon of bleach add 4 ounches of acid, right? If you add two gallons of bleach then 8 ounces of acid. Make sense?

Thanks in advance!

-Bill
St. Louis, Missouri

chem geek
04-18-2012, 02:22 AM
While Clorox Regular bleach (in the U.S.) is 6%, most off-brand regular bleaches are 3% or less, but the off-brand Ultra bleaches are 6%. As for what is in bleach, if 6% sodium hypochorite, then it also has 4.7% sodium chloride (salt) with the rest, 88.7%, water. There is a very small amount of excess lye, the amount varying by brand, but in Clorox Regular it's around 0.06%.

PoolDoc
04-18-2012, 06:31 AM
So, in every gallon of 6% bleach there is 120 ounces of water. What do you guys think the quality of that water is? What do you think the total disolved solids and calcium hardness is like?

Actually, there are more like 128 fluid ounces -- the sodium hypochlorite is dissolved in them. As for the water quality . . . it's pretty close to distilled. It messes up the manufacturing process when it's not.

chem geek
04-18-2012, 10:33 PM
You can read how Odyssey Manufacturing (http://www.odysseymanufacturing.com/about_product.htm) goes to great pains to remove even trace metals from the water because it can cause the chlorine to degrade too quickly and to produce too much oxygen. For every 10 ppm Free Chlorine (FC) from sodium hypochlorite (or lithium hypochlorite), it results in 17 ppm sodium chloride salt. Half of this is from the salt in the initial product and the other half is from the chlorine when it gets used/consumed as it becomes chloride. ANY chlorine product will produce 8 ppm salt from 10 ppm FC. However, Trichlor and Dichlor will also add 6 ppm and 9 ppm Cyanuric Acid (CYA), respectively, while Cal-Hypo will add at least 7 ppm Calcium Hardness (CH) in addition to salt from the usage/consumption of chlorine.