The Dos and Don’ts of Making Bleach with Pool Shock: Expert Tips and Tricks

Emergency situations can make clean water hard to come by and a potential spread of disease can make it extremely important to sanitize commonly touched items in your home. The good thing is bleach can do both of these things, but it doesn’t last that long on the shelf, and storing gallons of bleach will take up quite a bit of room. This is where pool shock comes in.

Mixing one heaping teaspoon (1/4 oz.) of granular calcium hypochlorite (HTH) into 2 gallons of water will make a chlorine bleach solution roughly equivalent to normal household bleach. You can use it to clean, sanitize, and disinfect water.

Let’s look at using pool shock to make bleach a little more closely.

Making Bleach with Pool Shock

Making bleach with pool shock starts by choosing the pool shock that contains the right ingredients. Figuring out what ingredients will work is probably the most confusing thing so I’m going to try to make it easy.

What you want in pool shock:

  • 73% calcium hypochlorite (HTH)
  • 70% available chlorine content

How to Make Bleach with Pool Shock

There are obviously other ingredients in pool shock, but they aren’t necessarily bad in the very small amounts that will be in your bleach mixture.

Don’t use lower-strength calcium hypochlorite (HTH) pool shock or anything that uses a chemical other than HTH. If you absolutely have to use lower HTH content pool shock then you can use 68% calcium hypochlorite (65% available chlorine) but your numbers will be a little different. 73% calcium hypochlorite is the preferred mixture.

I personally buy the pool shock that comes in 1 lb. bags instead of the buckets because one pound will make at least 200 gallons of bleach solution. It’s probably going to take me a long time to go through that much bleach! Each bag of pool shock is good for at least 10 years but once it’s mixed the bleach solution is really only at full strength for about 6 months.

Examples of pool shock that we’re looking for: Rx Clear Mega Shock, Zappit 73, and DryTec Extra Shock.

Using numbers that come straight from the EPA, you’re going to mix 1 heaping teaspoon of high-test HTH (73% calcium hypochlorite) to 2 gallons of water to make a bleach solution similar to household bleach. This solution will kill germs, strip the color out of fabrics, and disinfect water the same way that household bleach will.

To purify water, add the bleach solution to water in a 1:100 ratio. This comes out to one pint to 12.5 gallons of water or 1.25 oz to 1 gallon of water.

You can make a cleaning spray that will disinfect surfaces by mixing the bleach solution in a 1:10 ratio with regular water. This is great if you’re stuck in quarantine or just trying to prevent the spread of disease.

The important numbers:

  • Pool shock with 73% calcium hypochlorite (70% available chlorine)
  • Mix one heaping teaspoon (1/4 oz.) of pool shock into 2 gallons of water to make bleach
  • Make a disinfectant for surfaces by mixing the bleach solution 1:10 with normal water
  • Disinfect drinking water by adding the bleach solution in a 1:100 ratio (1.25 oz of bleach mix to 1 gallon of water)

Advantages Over Household Bleach

Storing pool shock has a lot of advantages over storing household bleach, but there are really two main advantages that stand out to me…shelf life and storage space.

The shelf life of store-bought household bleach is only about 6 months. After that, it begins to lose its potency and will gradually continue to decrease over time. It’s not really a big deal if you’re just using it to wash clothes.

It’s when you start to mix it with drinking water for purification that the loss of potency can get a little concerning. You just don’t know if you put enough in if it’s lost some of its strength.

By storing pool shock you get 10+ years of shelf life and can mix it on demand. That’s a lot better.

The other great thing with pool shock is the fact that it takes up so little space. Six 1 lb bags of pool shock fit in a box that’s about 6″ x 6″ x 12″. That’s enough to make 1200 gallons of bleach! Having that much potential bleach in suck a small package is pretty amazing.

The only trouble (if you can even call it that) with storing it is that it does put off a slight chlorine smell so I wouldn’t store the bags near any food products.

Why Bleach is so Important

Bleach is an amazing disinfectant! It alters the proteins in microorganisms that will quickly kill bacteria, viruses, and fungi. The low cost and availability of bleach make it important throughout the world to treat water and clean surfaces.

Uses for Bleach During a Disaster

Bleach has a lot of different uses before, during, and after a disaster.

How to Make Bleach with Pool Shock

Purifying Water

Purifying water is one of the most often talked about uses for bleach, and in some parts of the world, it’s one of the few ways to make sure that you’re getting drinking water that’s clean enough for drinking. Even in developed parts of the world, chlorine is pretty much universally used to treat drinking water.

To use your bleach mixture to purify drinking water, add 1 part bleach mixture to 100 parts water. This comes to right around 1.25 oz per gallon.

Before you drink the water it should have a slight chlorine smell. If you can’t smell the chlorine, then you need to add more.

As the water sits, the chlorine will naturally off-gas. You can speed this process up by pouring the water back and forth between two clean containers.

Cleaning After A Flood

A flood is one of the most destructive types of disasters that you can experience. Even if it’s just your basement that floods, the floodwaters can be contaminated with all kinds of waste and microorganisms. Everything that the floodwaters touch has to be assumed to be contaminated!

Use 1 cup of bleach to one gallon of water to kill mold. You probably want to get rid of most things that got wet during the flood, but you can also use bleach to wash things that you need to keep.

Disinfecting During a Pandemic

A pandemic is the worldwide spread of a disease that can’t easily be contained. If you experience this type of disaster, then having plenty of bleach on hand will let you routinely decontaminate things like doorknobs, countertops, and food preparation surfaces so you limit the spread of the disease.

A 10% bleach mixture is great to clean these types of surfaces. Clean them several times a day until the threat of the disease spreading has passed or a vaccine is developed.


Bleach is often overlooked as an item that should be on your shopping list when you’re out buying preparedness supplies, but it’s actually extremely important. The bad thing is traditional store-bought bleach takes up a lot of space and only has a shelf life of about 6 months to a year if you’re lucky. This is where pool shock comes in.

Pool shock takes up a lot less space and stores for 10+ years. All you need to do is mix it with water and you have a bleach mixture that’s just as good as any other kind of bleach and can do all of the same things. Also, make sure to properly dispose of any old chlorine.