Home Prepper Using Bleach to Purify Water, The Good, The Bad & The Ugly

Using Bleach to Purify Water, The Good, The Bad & The Ugly

by Anthony

Purify Water with Bleach

Last week we published a very popular article on storing water for long term.  In that article I briefly talked about purifying water. I decided to write an update to clarify using bleach as a purification method.

Typical household bleach is one of the more popular ways preppers are planning to use to purify their water after disaster strikes. There is plenty to love about using the bleach method, but nothing is perfect. Life would be far too easy if clean, safe drinking water was nothing more than a few drops of bleach away.

In this article, we are going to discuss the good and the bad of purifying water with bleach. It is up to you to decide what you will do to make your water safe to drink.


  • Household bleach is extraordinarily inexpensive. You will pay under $2 for a gallon. This is much less expensive than any other chemical treatment.
  • You only need a few drops to purify a quart of water. In fact, eight drops of household bleach can purify an entire gallon of water. The dirtiest pond water can be made relatively safe to drink with a cap full of bleach or about sixteen drops, which means a single gallon will last you for quite a while.
  • Bleach is widely available. You don’t have to order it online or search out some Army surplus store to try and find what you need. It isn’t only sold at camping stores. Bleach can be found at convenience stores, gas stations and grocery stores.
  • Bleach does not discolor the water once it has been treated. Other options, like iodine, can leave the water with an off-color and an unpleasant taste. Bleach evaporates fairly quickly. It can leave behind a bit of a chlorine smell, but gently swirling the water and exposing it to air can help get rid of the smell.
  • Bleach is a multi-purpose tool that can be used in prepping. It disinfects surfaces, can sanitize surfaces and can even kill the Ebola virus if you were worried. With so many uses for bleach, there is no wonder it is sold in gallon jugs.
  • Bleach can kill mold and mildew. If you are holing up in a home, this is important. You can’t afford to be sickened by mold spores. If you are dealing with a disaster that involves flooding or heavy rain, bleach will be a necessity to ward off mold.
  • Bleach can be used as a pesticide. Again, if you are holed up somewhere and sanitation isn’t what it used to be, you are going to be dealing with a lot of pests. You cannot afford to have your food supply contaminated. Use straight bleach or a solution of bleach and water to kill ants, roaches or whatever bugs have invaded your area.
  • Bleach may be a bit stinky at first, but it eliminates nasty odors. It is an effective odor remover. Pour a few drops of bleach in the bottom of your trash receptacle to help reduce the odor. If the windows and doors must be closed, you want the air in your home to be as odor-free as possible.


  • Bleach does not store for long periods of time. It is only potent for about six months, which means it has a very short shelf life. The Clorox website insists the bleach is good for about a year after it is manufactured. However, that is not taking into account the time the bleach sits in their warehouse, the supplier’s warehouse and then on the store shelf. After six months, it is safe to assume the bleach is weakened.
  • Bleach is not effective against killing every single harmful contaminant in water. Protozoa has hard outer shells that bleach cannot get through. Cryptosporidia cannot be killed off by bleach or iodine. UV light or boiling water are the only real treatments to make the Crypto inactive. Crypto is in feces. An animal with Crypto that defecates in or near water can contaminate the water supply. Humans who have diarrhea may be suffering from Crypto. If they touch something after using the restroom and do not wash their hands properly and somebody else comes along and touches that thing, puts their hand to their mouth, they can become infected. The hard outer shell of the Crypto allows it to live outside the body for several days.
  • Bleach is poisonous! Humans can tolerate minuscule amounts of bleach diluted in water, but touching bleach or ingesting bleach is dangerous. The powerful fumes of bleach can also cause serious health problems. Bleach should only be used in an open, ventilated area. If you are in a small, bunker-type closet, opening a bottle of bleach could make you sick. Your eyes will water and burn and you may find it difficult to breathe.
  • Folks who have asthma may have an attack triggered by the inhalation of bleach. If you or someone in the family has asthma, it is best to treat the water in another area of the house or outside. Anybody who has asthma or other breathing problems may not be able to tolerate water treated with bleach. A survival situation is not the time to find out.

As you can see, bleach certainly has its purpose in prepping. Only buy bleach for prepping that is unscented. The flowery, pretty-smelling bleach is not useful for your prepping needs. Your best bet is to keep bleach on hand and make sure you properly rotate it. Use a market to mark the date you added the bleach to your supply and try to add a fresh gallon each month. If the bleach expires, you can use it to flush toilets in a survival situation. It doesn’t hurt to have an alternative method for purifying water, just in case that nasty Crypto is lurking.

You may also like

Leave a Comment


This site uses Akismet to reduce spam. Learn how your comment data is processed.

As an Amazon associate, we earn from qualifying purchases. This site also participates in various other affiliate programs, and we may get a commission through purchases made through our links. Please read our complete Disclosures and Privacy Policy for more information.