Stupid Question Alert: Liquid "Shock"


LifeTime Supporter
May 29, 2007
Milwaukee, WI
Hi Everyone:

I'm sure this is a completely stupid question, but, who else can I ask? We still have gallons of "Poly-Guard Ultra Shock" leftover from when we first opened our pool last month. (Before we found out about BBB.) The ingredient list says:

Active Ingredient
Available Chlorine: 15%
Sodium Hypochlorite: 12.5%
Inert Ingredients: 87.5%

Sooo, is this stabilized or unstabilized chlorine? We don't want to use this stuff if it's going to add any more stabilizer to our pool. CYA isn't mentioned anywhere on the label, but we're not sure if it's part of that vague "inert ingredients" description. Thanks for your help!


LifeTime Supporter
Mar 29, 2007
SE Louisiana
That's just super strength bleach. You can use it as you would any other bleach; just remember it's twice (or more) the strength of "ultra".

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
San Rafael, CA USA
The "Inert Ingredients" is just water and salt (i.e. salt water). The salt is a byproduct of the manufacturing process when chlorine is put into lye. Salt is also found in Cal-Hypo and Lithium Hypochlorite.

Note that the 15% concentration (probably Trade %) is rather high and will degrade somewhat quickly unless you store this chlorine in cool conditions. See the chart at the bottom of this link where you can see that 15% chlorine will lose half of its potency in 2 months at 85F, 3 months at 80F, etc. A concentration of 12.5% Trade (% available chlorine by volume) or sometimes 10% is more typical. Most bleach is 5.7% (trade) for comparison (this is marked 6% sodium hypochlorite by weight on the bottle).