Liquid Shock from Ollie's


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Liquid chlorine is just the same as bleach but at a higher concentration, so you can use about half as much compared to 6% bleach. There isn't anything in it that you need to watch out for. The only real difference is that the higher the concentration the quicker it goes bad. At 12.5% you have a couple of months if you keep it cool, but it can go bad if you leave it in the sun or it gets too hot. While with bleach you have a year or more.


Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
Tucson, AZ
This actually addresses a question I had about this. You say with the 12.5% if it gets warm or if its in the sun it will "go bad".

From reading various things here, I thought that the higher the concentration and the higher the temp/sun, the shorter the half life. So, your 12.5% bleach, if subjected to high temps/sun with drop to 6% in a month or so. But, then shouldn't the half life now be the same as 6% bleach? Or does it not quite work this way?

Does the blanket statement of "going bad" really just mean the the actual chlorine level will likely be less than the sticker, but still "good" in the sense that there is nothing wrong with it other than having a lower content and not "really" knowing what levels you are adding to your pool?

Although given this quick drop and not knowing how the store handled/stored it, is the fear that you may be buying something with no more chlorine in it than you would have gotten in 6% bleach for less money?


TFP Expert
LifeTime Supporter
May 10, 2010
SW Louisiana
Just be careful that it is fresh, as others have noted it looses its strength with time, and the higher the concentration the faster it is lost. I was in the local Home Depot a couple of weeks ago and noticed they had multiple pallets of liquid chlorine in their garden center that had obviously been there since last summer or longer (sun faded labels, and rotting cardboard spacers). I can't help to wonder how weak it is now.



Well-known member
May 2, 2011
lebanon tn
I wonder if they would let you test it before purchase? or if they'll refund if substantially weaker than labelled?

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
San Rafael, CA USA
jblauert said:
So, your 12.5% bleach, if subjected to high temps/sun with drop to 6% in a month or so. But, then shouldn't the half life now be the same as 6% bleach? Or does it not quite work this way?
Yes, it pretty much works that way though degrading by half won't just have more chloride salt, but chlorates as well. It's best not to intentionally have the chlorine lose its strength and use it on a regular basis. If it happens once in a while, that's OK.


Jun 29, 2015
If it's Kem Tek they told me they have a date code on the plastic jug not the label that starts with the year followed by the numerical day of the year it was made: 2015180 would be the 180th day of 2015 so it's probably worth checking.


Jul 3, 2015
Albany, ny
Regarding the price, my local supplier charges $15-16 for a blue 5 gallon jug of the 12.75% chlorine shock. So the price you reference really isn't a sale price. At least not in the northeast. It's about a fair price. Bout it. Just fyi.


Jun 29, 2015
If fresh (and still 12.75%) that's about $3.14 per pound of available chlorine which is a very good price compared to our options here in Columbia, SC. of over $5 per pound for clorox. In fact that's not much above granular calcium hypochlorite's $2.45/pound when bought in 100 pound drums for $159. (65% active chlorine) and well worth it considering the hardness increases and high acid demand from the granular stuff. If I could buy liquid chlorine here for anywhere close to that I'd definitely switch since my long term use of stabilized tablets has increased CYA to unacceptoible levels and current use of unstabilized granules is increasing hardness and either way I will end up having to drain a major portion of the water.

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