Do you need to use chemical preservatives?

John AdamaStaff - December 21, 2020

Do you get your water from the grid in a developed country? Then no, you don’t need to add any chemicals or do anything else to tap water before putti
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The shelf life of bleach is just 6-12 months. Because of this, I bought one pound of calcium hypochlorite from a pool supply company. This stuff has to be stored very carefully, e.g. NOT in its original plastic bag and not in a metal container or a container with a metal lid. It is dangerous stuff because it is so reactive. But its shelf life varies from 2 years on up, depending on whom you believe.  Mixed in very small quantities with water, it will provide a disinfectant, not just for purifying water but for other needs, such as cleaning up after a sewage backup, which is entirely possible if electric power is out for an extended period. Do others have experience using or storing Ca(ClO)2? Does ThePrepared recommend this product? Safe storage is the primary issue.

 

Great question. For others reading: Ca(CIO)2 = calcium hypochlorite, commonly referred to as “pool shock.” You can think of it as dehydrated bleach.

Advanced preppers will store pool shock for exactly the reason you described: it lasts longer than common bleach, is more storage-space efficient because it’s a concentrated powder instead of a liquid, and has potentially more versatility.

So yes, we recommend it for people who wouldn’t otherwise use/rotate through bleach or similar shorter-term chemicals enough to keep the supply fresh. If you don’t have a pool or use bleach/chlorine for anything else in your life, but want to have some on hand that you buy and forget about until the emergency, then this is the way to go. Just be safe about storage. 

But it’s also just as fine, and easier for most people, to just buy and rotate a small cheap bottle of liquid from the local store.

 

Thanks for this great course. I have my containers and am ready to fill them.  I have a whole house water filter, which is supposed to take a lot of the chlorine out for better tasting water.  So, should I add bleach (using the quantities you outlined above)?

 

If you’re not sure what your home filter removes from the water / worried it might take out the healthy preservatives (which some do), then it’s totally fine to add some bleach to err on the side of safety. Go with the lowest end of the quantities talked about in the class, since the water is otherwise very clear.

 

What about using sodium hypochlorite powder? I see it is available in various quantities on the web.

 

Personally I would lean more towards the pool shock (calcium hypochlorite) because there is more data on people using it on a personal level, even the EPA lists how to use it.

From what I can tell, sodium hypochlorite is more so used to treat water in city water treatment facilities. I was able to find one research study though that gave guidance on how to use it:

• 1.88 mg/L and used within 24 hours for low turbidity sources
• 3.75 mg/L and consumed within 8 hours for higher turbidity sources

So it seems like you could use sodium hypochlorite and it’s probably better than nothing. But without more evidence of people using it personally for storage/treatment, I err on the side of caution and stick with what’s known.