Testing Bleach Strength: 1.88ml in 5 gallons of Water

Since high strength liquid chlorine is rather unstable, and I just bought a carboy of 12.5% yesterday, I wanted to see if it was truly 12.5%

We know, from the Bleach Calculation formula, that 1 gallon of 12.5% Liquid Chlorine will add 12.5ppm of FC to clean water (ie, with nothing to metabolize).

1 gallon contains 128 fluid ounces and one centiliter (10 ml) equals .34 fluid ounces.

Therefore, if you add 1 ounce of 12.5% to 78 1/8 gallons of water, you should get the same 12.5FC reading.

0.34 time 78.125 gives you 26.56 gallons. Therefore 10ml of 12.5% liquid chlorine should get the same 12.5FC reading in 26.56 gallons.

Divided by 5 and 2ml of liquid chlorine should get the same reading from 5.3125 gallons.

Adjust down for 5 gallons exactly, and 1.88ml of Liquid Chlorine should keep that reading.

So, if you pour 1.88ml of bleach/liquid shock/liquid chlorine into 5 gallons of fresh water, you should get the same FC reading as if you dump 1 gallon into 10,000 gallons of water.

On Ben's PS-232 kit, the OTO/pH cell has a side marked to 1.8ml. I used that to check my work. It wasn't as precise as I would have liked because I goofed and added the 1.8 and a little to 5 gallons of pool water:o

I got a reading of 19.5 FC. Then I tested the pool water and got 5.5, indicating that my 12.5% was 14%--I AM dubious that it's stronger, but at least it tells me the 12.5% hasn't started to degrade. I'm recycling a lot of bleach jugs...Filling them halfway with tap water, then the rest of the way with 12.5%--it should give me gallons of 6% that I hope is more stable.

I would VERY much appreciate somebody checking my math and my assumptions.

Thanks!

Using ratios:

1 / 10000 = x / 5

x = 5/10000 gallons, .064 ounces, 1.88 ml

You got it right.

Thanks Carl! I'll be trying this out to see how my chlorine is :D

can't wait...


I just found a new place to buy chlorine from. They fill the chlorine in a black 5.5gallon container. They mentioned that the have their chlorine tested often...and that it comes in at 17%, but they will never let it drop below 12%. So it wouldn't surprise me that yours is also above 12%.

I think I may test my chlorine every month...just to see what I'm dealing with and how fast(or slow) it does lose it's concentration.

take care,
dan

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Originally Posted by CarlD

I got a reading of 19.5 FC. Then I tested the pool water and got 5.5, indicating that my 12.5% was 14%--I AM dubious that it's stronger, but at least it tells me the 12.5% hasn't started to degrade.

Thanks!

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Carl, we have 2 huge tanks of chlorine where I work that get filled weekly to every 10 days...I asked about the strength and they (the company we get it from) told me it is 17-18% when they deliver it so it will be at least 12.5% when we sell it. We sell a LOT of liquid chlorine so I think the stuff we sell is at least 14% when it is sold! We sell a 2.5 gal refill for $3.69. The jugs are under $6 if someone doen't have one for refill so I think we are the best bargain where I live for chlorine.
IF you are really interested in checking the strength Aquachek makes a high range chlorine level test strip that will test up to 60 ppm
http://www.aquachek.com/products.asp?n=1&l=1
and Taylor makes test kits for testing bleach strength
http://www.taylortechnologies.com/pr...D=2&KitID=2190
http://www.taylortechnologies.com/pr...D=2&KitID=2191

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We sell a 2.5 gal refill for $3.69.

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DANG!!!!, Evan! I wish you could ship that to me!!! I paid $17 for 5 gallons--that's about what you pay up here. So it might WELL have been the 14% I measured.

Vedddddy Interesting!

I realized if you add 1 ml to 10 liters (as in refilling a 2 liter Coke bottle 5 times) you'll get the same results, too. Just keep it all metric--and it will be easier.

BTW, I recently discovered that they sell spigots for the carboys. What a difference they make! Worth every nickel!

See, there ARE some decent pool stores! (we are an Ace Hardware with a huge pool department! We even sell above ground poolsl....Real ones by Cantar and Zodiac!) (and if ANYONE refers to me as the 'Helpful Hardware Man' they will be very sorry!;))

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Originally Posted by waterbear

and if ANYONE refers to me as the 'Helpful Hardware Man' they will be very sorry!;)

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Not if you can't ship me chlorine at that great price!:D