Well, I may have bought the wrong thing. K-mart is selling 96oz bottles bleach for $1.00. That's about the best price I have seen for a while. So I went to check it out. The first thing I noticed is that the label doesn't give the percentage of sodium hypochlorite. In the past, I stay from the procuct. This time, I'd give it a try. My plan is/was to test the FC and treat the entry in the Pool Calculator as 6%. I would add the amount recommended then test the water an hour later to see if I reached the target level. If it didn't, I'd adjust accordingly.
So I bought three cases and came home. While unloading the boxes, I noticed the box had printed on it "ingrediants-water 7732-18-5: sodium hypochlorite 7681-52-9: sodium hydroxide 1310-73-2. (I just included the numbers because they were there.) I know that sodium hypochlorite is chlorine. I googled sodium hydroxide and found that it's also known as lye and caustic soda. Will the sodium hydroxide hurt my pool?

That is fine, regular bleach, just with a more detailed label than usual. There is always a little tiny bit of lye in bleach, usually too little to be able to measure. Lye is dangerous to handle in pure form, and completely harmless once dissolved in the pool. Basically all it does is raise the PH, and since the quantity is very small it will raise the PH so little you won't notice.

Thanks, Jason.

Love you guys

That is good to know!
Time to hit up our local K-Mart and see if they have it for that price here!
Our Atwoods has their bleach on sale for $.99 now too.

You should only get bleach that has

Sodium hypochlorite.....6.00 %

on the label. If it does not say 6 %, it probably is much weaker.

Sounds like a good time to check the local Kmart for a few bottles ...

True. The msds on the sowhite bleach from atwoods is only listed at 5.25% sodium hypochlorite. But as long as you use that percentage in the pool calculator you will be ok because it will calculate the proper dosage based on the percentage.

Simple explanation:
http://www.thenakedscientists.com/forum/index.php?topic=38281.0

Kinda cool stuff.. but then again, I'm a chemist so this stuff tickles my funnybone:
BTW... this one talks just a tinnnnnny bit about chlorine from salt.
http://www.bleachtech.com/ourprocess.html

The numbers (7681-52-9 etc) are from the CAS... Chemical Abstract Service which is a huge database of known chemical compounds. The numbers help chemists and others find information about the compound's chemical and physical properties and it can help medical and emergency personnel should something happen like a poisoning, fire, or something else.

-wc

Three years ago, all I could find around here was 5.25% in gal. bottles. Two years ago, I noticed the bottles were 96oz. and at the same price of the old gal. bottles. I was p.o.ed. They were ripping us off. When I read the new labels and saw 6%, I cooled off a bit.

As I tried to say in the first post (I see I left a word out), in the past, if the label didn't list the percentages, I wouldn't buy no matter how good the sale. I decided to break that rule, yesterday. I haven't tested the water, yet, this a.m. Depending on the reading, I may wait 'till tonight to use the 'new' bleach. I want to have to raise the FC a significant amount for the test. I'll use 6% in the calculator, add the indicated amount of bleach and test an hour later to see if the benchmark was reached. Hopefully, it'll give me an idea the % number of the 'new' bleach. I'll post the results.

KMart bleach or actually smart sense is listed as 6-7% on its msds

This is Crystal branded. Sold in the K-mart dollar section. I haven't had time to run an 'eyeball' test to try to estimate the %. I may try this evening after the sun goes down to eliminate chorine loss due to sunlight.

Well, I've been used the cheapest K-mart bleach for two days now. Even though the label doesn't list the %, if it's not 6% it's darn close to it. I will buy it again without any second thoughts.

I hope this isn't the crystal bleach you are getting only 2%

http://www.jamesaustin.com/PDFS/Crystal%202%20080211.pdf

Could be...hope not

I've tested the FC and plugged the number into the pool calculator using 5.25% as my number. Added the suggested amount and then tested again an hour later, my new FC was .5ppm within my goal. I did this three days in a row.

Regardless, I don't think I'll buy bleach again if they don't list the percentage on the label