# Thread: Testing the strength of 12.5% chlorine

1. ## Testing the strength of 12.5% chlorine

Is there any way other than using the Pool Calculator, adding chlorine to the pool and seeing the results to find out if my 12.5% is 12.5%? I just started using 12.5% and I know it loses strength quickly, so how do I know it's full strength when I buy it?

2. ## Re: Testing the strength of 12.5% chlorine

It takes some pretty accurate equipment to get an accurate test of strength of the bleach.

You can use the pool calc if the 6% has been pretty accurate in the past. 12.5% should take half as much to raise it the same amount.

3. ## Re: Testing the strength of 12.5% chlorine

Couldn't use the pool calculator to figure the amount to use in a known smaller volume of water, say 5 or 10 gallons, add that amount to figure the strength based on FC rise.

4. ## Re: Testing the strength of 12.5% chlorine

Using the Google-Search field in the very bottom left of the page, search for "test chlorine strength", without the quotes.
Here's the first one:
testing-strength-of-liquid-chlorine-t3165.html

6. ## Re: Testing the strength of 12.5% chlorine

Thanks for the replies. I did a search and surprised I didn't get the thread ohm boy linked. I want to check my supplier to see what I'm getting.
Thanks again.

7. ## Re: Testing the strength of 12.5% chlorine

1/4 teaspoon of 6% bleach in 2 gallons of chlorine-free (and chlorine-demand-free) water is 10 ppm FC. 1/4 teaspoon of 12.5% chlorinating liquid in 2 gallons is 20.4 ppm FC so 1/8th teaspoon is 10.2 ppm FC.

If you have a spare Taylor or TFTestkits bottle from one of the reagents (especially the titrating ones), then they are 24 drops per ml so 24 drops is 1/5th teaspoons. 1/4 teaspoon is about 30 drops. 1/8th teaspoon is around 15 drops.

8. ## Re: Testing the strength of 12.5% chlorine

Thanks again everyone. I'll try it chem geek's way and the method from the link ohm boy posted and compare results. Thanks for the link James but \$83.50 for the Taylor Test is a little steep for now.

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