Question about Trichloro %


Active member
Jul 18, 2014
Deptford, NJ
Love the site and all the help I have gotten here. My question is about % of ingredients when I look on a package. For example when I see trichloro tablets it says 93.6% trichloro, and when i look at pool schock that uses trichloro it says 43.46%. Does this mean the say one 8oz tablet has about the same chlorine power as one 16oz bag of shock?

Also when I use the pool calculator which trichloro concentration is that set to? It seems to me that the same amount of trichloro tablets would have double the effect of the pool shock.

I appreciate any insight .


TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
NW Ohio
The quick answer to your question is yes, you are correct. If you want to use PoolMath (we do not recommend Pool Calculator) to calculate impure trichlor use then some simple math will be required. An 8 ounce tablet that is 93.6% pure has 7.5 ounces of trichlor in it and a 16 ounce bag of 43.46% has 7 ounces.

The long answer is that we discourage regular use of trichlor tablets, highly discourage the use of trichlor tablets that aren't pure (what is the other 6.4%?), and I will outright say that there is no good reason to use powder trichlor shock. Trichlor shock is very weak (as you pointed out) because they cut it with baking soda to offset the extreme acidity of trichlor and any reason you would want to use it over liquid chlorine (why would you anyway?) is easily found in better solid chlorine options.