One of the main components that you’ll want to have around the house (or apartment) during a SHTF situation is chlorine bleach. Not only can it be used for cleaning water (although boiling is hands down more effective and healthier) it is excellent for keeping things sanitary.
Unfortunately, the average shelf life of liquid bleach (being stored between 50 and 70 degrees Fahrenheit) is around 6 months. After that, bleach will lose 20% of it’s strength at around the year mark and then 20% each year after that. So if you’re not vigilant about keeping it rotated, chances are when you need it for disinfecting water or to keep things clean you’ll be fresh out of bleach and luck.
There is a better option. What if you could make your own fresh chlorine bleach that could be used for both keeping things sanitary and will disinfect water? Here’s how:
How to Make Chlorine Bleach
Before we go into how to make it, I just wanted to point out the differences between this homemade chlorine bleach and your standard household Chlorox variety.
First off, liquid chlorine bleach is a solution made from mostly water and 3-6% Sodium Hypochlorite. This homemade variety is made from Calcium Hypochlorite which you can easily find as “pool shock” at your pool-supplier store or Walmart. Both are used throughout the world for water purification and are the main chemicals in standard household cleaning products.
The Benefit of Calcium Hypochlorite
The major benefit of using Calcium Hypochlorite over Sodium Hypochlorite is shelf life. Calcium Hypochlorite (pool shock) is sold in a solid granular form and has a 10 year shelf life when stored in a cool, dark place. This will easily meet your long-term storage needs.
The other benefit is the amount of available chlorine. The concentration of chlorine is much higher with Calcium Hypochlorite. For example, a small 1-pound bag of calcium hypochlorite can disinfect up to 10,000 gallons of drinking water. That’s around 5 gallons/day for one person for 5 1/2 years! Not bad for only 1 lb of granules.
Making Chlorine Bleach
To make a chlorine bleach solution using calcium hypochlorite, here are some formulas I got from the Army Technical Bulletin entitled, “SANITARY CONTROL AND SURVEILLANCE OF FIELD WATER SUPPLIES” (TB MED 577).
From the Army manual, to make a concentrated chlorine solution that you can use for disinfecting water (or to be used in maintaining a clean and sanitary living environment), you’ll want to use calcium hypochlorite that has around 70% available chlorine.
If you’re buying pool shock, on the back of the bag it will tell you what percentage of chlorine is available. The one I use is called “Zappit 73 Pool Shock, it is pure calcium hyphochlorite that contains up to 73% available chlorine and sells for around $5 for a 1lb bag.
To make the homemade chlorine bleach solution, you’ll need to do the following:
- Mix 2 level Tablespoons of Calcium Hypochlorite to 3 cups of water.
After you’ve made your stock of chlorine solution, you’ll want to follow the formula from the Army Technical Bulletin in determining how much of the above stock chlorine solution you’ll need for your desired number of gallons of water to be disinfected. *Note: I’ve updated the formula to calculate the same concentration that household bleach has. If you have questions, fire me an email and I’ll be more than happy to explain the math.
mL of stock chlorine required = (desired concentration (mg/L)*number of gallons to be treated)/18.12
The desired concentration refers to how much chlorine in mg/L you want the disinfected water to have. A recommended amount is 7 mg/L of concentration. This equates to adding 8 drops of household liquid bleach to 1 gallon of water (the recommended amount when disinfecting water with household bleach).
Given these amounts, if you wanted to disinfect 1 gallon of water with the homemade chlorine solution, the formula would be as follows:
This equates to .38mL or 8 drops of the concentrated solution per gallon of water. Just like normal household bleach!
So the 3 step process is as follows:
- Place 8 drops of homemade chlorine bleach in 1 gallon of water
- Let stand for 30 min
- If water is still cloudy, repeat steps until clear; otherwise it is ready to drink
Keep in mind, that once the homemade chlorine bleach is made it will follow the same shelf-life limitations as standard household liquid bleach. So be sure to only make amounts you will be using within that time frame.