We are cautioned to only use "fresh bleach" for our water storage. What is "fresh" bleach? For one thing, bleach has a shelf life of only 12 months. So, I'll fill you in on what the people at Clorox told me about deciphering the code stamped on their bleach bottles.
My bleach bottle has two lines stamped, and we only need the top line. Mine says "A8810514". Translation:
* A8 is the plant number where product was manufactured * Third digit is the year produced. This will always be a single digit number. When we get to 2010, it will have a 0. * Next three digits are the number of the Julian date code, which tells the day of the year manufactured. This will be listed as the number of days into the year, such as 116 days (116) or 30 days (030). It's always three digits. There are Julian code converters on the web, but you can get a good general idea by dividing 365 by thirds without being perfect with it. * The rest of the numbers thereafter are not important
For practical purposes, the lady told me that you only need to check four numbers of the code: the third number from the left, which tells you the year and then the next three numbers to see which day in the year the bleach was produced.
If you want to get bleach that is as fresh as possible for water storage, find a store that sells a lot of bleach. Everything I've read is that you want to buy Clorox regular, without scents and such. The reason you use Clorox for water storage is that it has a set amount of chemical and some bleaches are more watered down. If you make sure you have the same amount of chemical in another brand, I imagine that's fine, but I don't know.
Another option for water storage is to use the powdered chlorine that is used in spas. The powder has at least a 15-year shelf-life, but I have yet been unable to get in contact with the expert to tell me how much to use per gallon.
The nitty-gritty of this is that if we use bleach to keep our water safe, we need to refill our water storage containers every year and put in fresh bleach -- I don't think it's a good idea to just add new bleach to water to which you're already added bleach a year ago, as you then have double the chemical, even if the old stuff is not as effective.
If you're still trying to decide where to put your huge water containers, having to empty them and refill them every year might make you decide NOT to put them in your basement. Put them where you have easy access. My barrels are in my garage. Some people store them outside. If stored outside, you will want to leave some unfilled space at the top in case the water freezes completely.
Most important is FILL THOSE BARRELS!!! Soon, the weather will be very cold and you're not going to want to be outside messing around with hoses and water.