Can You Use Bleach in a Pool? (Is It Safe?)

Many pool owners want to know if you can use bleach or Clorox to sanitize your pool. It’s a common question and one that is more than a simple yes or no answer. It is important to know what exactly bleach is before you put it in your pool. 

Before we dive in, here is the quick answer.

Household bleach, Clorox and liquid chlorine can all be used to sanitize a pool. They are all types of chlorine. Household bleaches such as Clorox usually contain about 5-6% available chlorine, about half that of pool liquid chlorine. Household bleaches often have unwanted fragrances and colors.

While bleach Clorox can be used to sanitize your pool, there are a lot of other factors that should be considered before running out to the store. We’ll cover all these factors in detail to help you decide if you should use household bleach or Clorox in your pool.

What is Bleach?

Depending on where you’re from, bleach can mean different things to a pool owner. One person may mean the liquid pool chlorine that is sold in the pool store when they say bleach. Others may be referring to household products like Clorox and those sold in Target and Home Depot.

Household bleach and Clorox are both chlorine or sodium hypochlorite. Yes, the same chlorine that you use in your pool, but many things about it make it different from your typical swimming pool liquid chlorine or other pool chlorines.

In fact, some people call pool chlorine bleach, regardless of the type. There are differences between household bleach and pool chlorine bleach (liquid chlorine) though.

Household bleach and Clorox typically come in half-gallon or one-gallon jugs. One gallon of bleach is going to have 5-6% chlorine; the rest is mostly water and some salt. Some Clorox options can contain up to 8% chlorine. 

When you are sanitizing your pool, you want products that have a higher percentage of chlorine. This is the strength of the product. The higher the percentage, the less of it you will actually have to use. 

You can easily find the percentage of chlorine in a bottle of bleach or Clorox, or any product for that matter, by looking at the label on the bottle. 

For a pool that is 10,000 gallons, if using Clorox, which contains 6% chlorine, you will need about 21 ounces to raise your available chlorine by 1 ppm. Remember that one gallon is equal to 128 ounces, so if you were to add 1 ppm daily (if needed), a gallon of Clorox will last you about 6 days. 

According to The Scripps, household bleach or Clorox will have a shelf life of about 6 months. After that, it loses about 20% of its original effectiveness each year. So you’ll need to use it quickly.

Related Reading: Which Pool Shock Should You Use? (answered!)

What’s the Difference Between Bleach/Clorox and Pool Liquid Chlorine?

Household bleach, Clorox bleach and liquid chlorine, are both capable of achieving the same goal, which is to sanitize your pool. However, the main difference between pool store chlorine is it is much stronger (12.5%) compared to bleaches like Clorox (6-8%).  This means you’ll have to use more of it to sanitize your pool than you will if you use liquid chlorine made for swimming pools. 

Clorox is going to have a much longer shelf life than pool liquid chlorine, 6 months compared with 6 weeks for pool liquid chlorine. 

Here is a breakdown of the similarities and differences between Clorox and liquid chlorine

	Household Bleach	Liquid Chlorine
Available Chlorine	5%-6%	10%-12%
pH	12.5	Up to 13%
Contains Stabilizer	No	No
Shelf Life	6 months	Weeks
Ounces to Raise 1 ppm*	21 oz	12.8 Oz
Price Per Gallon	$2.60 (Walmart)	$4 (Walmart)
Cost to Raise 1 ppm	$0.43	$0.40

Is Clorox or Bleach Cheaper than Pool Chlorine?

Household bleach and Clorox cost about the same amount to raise swimming pool chlorine levels by 1 ppm. Household bleach and Clorox cost about half that of swimming pool liquid chlorine by gallon. However, given that Clorox and household bleach are about half the strength of swimming pool chlorine this false economy.

There are other pool chlorines available, too. We have an article on Liquid Chlorine Vs Chlorine Tablets here.

Costs Comparison of Bleach/Clorox vs. Liquid Chlorine vs. Cal-Hypo

As you can see by the table below, bleach, pool liquid chlorine, and calcium hypochlorite cost about the same to raise swimming pool chlorine levels. The cost to buy each product may seem different, but when you take into account the difference in the chlorine strength of each product, they are very similar in cost.

	Bleach/Clorox	Liquid Chlorine	Calcium Hypochlorite
Ounces to Raise Chlorine 1 ppm*	21 oz	12.8 Oz	2 Oz
Price	1 gal = $2.60  (Walmart)	1 gal = $4  (Walmart)	50 lbs = $180 (InTheSwim)
Cost to Raise 1 ppm	$0.43	$0.40	$0.45

Is it Safe to Use Clorox or Bleach in a Pool?

Clorox and household bleach are both safe to use in a swimming pool, provided there are no added fragrances, colors, or other additives.

It can, however, be difficult to find the exact additives for some household bleach products, so it may be worth sticking with swimming pool chlorine unless you know for sure.

Both products are safe for swimmers as they are the same chemical, sodium hypochlorite. And they both safely sanitize pools as long as the correct amount is added. Downsides of Using Clorox or Household Bleach in a Pool

Pros and Cons of Using Bleach to Disinfect Pool

Check out the chart below for a quick breakdown of all the pros and cons of using bleach.

Pros

Does not contain stabilizers

This is both a pro and a con. If your pool water already contains a stabilizer, you won’t further increase the levels.

Long Shelf Life

The advantage of using Clorox or bleach is they have a shelf life of about 6 months, so you’ll waste less. Swimming pool liquid chlorine on the other hand is only good for about 6-8 weeks depending on the storage conditions and the age.

Readily Available

The best part is you can get it from your local grocery store, so you don’t need to visit a special pool supply store when you run out.

Cons

May Contain Coloring or Fragrances

Many household bleach products contain coloring or fragrances. If you use Clorox or bleaches with either of these, you could wreak havoc on your pool. There is potential for staining of your pool surfaces if you’re not careful and any fragrances in your bleach can be very harmful to your pool. 

May Contain Additional Unwanted Chemicals

Scented bleach contains additional agents to create and bond the fragrance. These additives can throw other chemicals in your pool off balance and be a pain to get back to proper levels. 

Some forms of bleach have been found to cause pool water to foam when the additives combine with the pool chemicals to create a reaction. If you accidentally add one gallon of scented or another form of bleach with additives, it’s nothing to worry too much about, but it’s definitely not something you want to add a lot of or do frequently. 

If you decide to use household bleach or Clorox in your pool, always be sure it is unscented and free of other additives.  

Much like liquid chlorine, the pH of Clorox is high. The pH of a gallon of Clorox is 12.5 which means that it could significantly raise the pH levels in your pool.

After adding Clorox to your pool, you’ll also need to use a pH decrease or muriatic acid to keep your pH balanced. Make sure to test your chemicals regularly to know exactly where they are at and make adjustments from there.

Clorox is not the only product that has side effects for your pool though. Calcium hypochlorite raises the calcium levels of your pool. Calcium hypochlorite is another type of unstabilized chlorine that will require added cyanuric acid, and it will also raise the calcium levels in your pool.

Don’t Contain Stabilizer

This was mentioned as a pro. But it can also be a con. If there is no stabilizer (cyanuric acid) already present in the water, any bleach product (including liquid chlorine) will break down within hours when exposed to sunlight. So it’s a must to add stabilizer or cyanuric acid for effective sanitization.

How to Use Household Bleach as Sanitizer in Swimming Pools

Using bleach as a sanitizer in your swimming pool is much like using liquid chlorine. You simply dump in the amount you have measured out to add the desired amount of chlorine and let it do its job. 

You want to make sure you’re adding the correct amount as too little will do nothing to sanitize your pool and too much, and your pool could be un-swimmable until the chlorine drops back down.

Clorox doesn’t contain any stabilizer so it should be added at night when the sun has gone down so that it won’t degrade too quickly. This will give it a chance to sanitize overnight with no UV rays or swimming activity.

Related Reading: What is Swimming Pool Stabilizer & When To Add It

How Much Bleach or Clorox to Use in a Pool

The table below shows you how much bleach, Clorox, or pool liquid chlorine you’ll need to raise your chlorine levels approx. 1 ppm.

Simply look at the strength of the bleach or chlorine you have and reference this with your pool’s volume. Normal pool chlorine levels should be 1-5 ppm. 

These are only approximate numbers as it will vary depending on your pool’s chemistry.

Pool Volume (Gallons)	5% Strength	6% Strength	12% Strength
1,000	2.5 oz	2 oz	1 oz
2,500	6 oz	5 oz	2.7 oz
5,000	12.5 oz	10 oz	5.3 oz
10,000	20 oz	21 oz	11 oz
20,000	50 oz	42 oz	21 oz
30,000	76 oz	62 oz	32 oz
40,000	101 oz	83 oz	43 oz

You can use this bleach or liquid chlorine here:

How Much Bleach for a 10,000 Gallon Pool

For a pool that is 10,000 gallons, add 21 ounces of 6% strength bleach or 6% strength Clorox to raise the available chlorine by 1 ppm.

Bleach Type	Amount to Add
Bleach (6% strength)	21 ounces
Clorox Bleach (6% strength)	21 ounces
Clorox Bleach (8% strength)	16 ounces
Liquid Chlorine (12.5% strength)	10 ounces

How Much Bleach is Needed for 10,000 Gallons of Pool Water?

Remember that one gallon is equal to 128 ounces, so if you were to add 1 ppm daily (if needed), a gallon of Clorox will last you about 6 days.

How Much Bleach for a 15,000-Gallon Pool?

For a pool that is 15,000 gallons, add 31 ounces of 6% strength bleach (or 6% strength Clorox) to raise the available chlorine by 1 ppm.

Should You Use Clorox Instead of Pool Chlorine?

Household bleaches such as Clorox are effective sanitizers for your pool, and you can use them. However, you need to be very careful not to purchase bleaches with fragrances, colors, and other additives that could cause big issues in your pool.

In some areas, perhaps household bleach works out cheaper, but we didn’t see that in our cost calculations.

The decision of whether to use Clorox instead of pool chlorine is really a personal one. Weighing the pros and cons and seeing what matters to you is going to help you make the best choice for yourself. 

Final Thoughts

Clorox and household bleach is an easily accessible product and one that is fairly cheap. It comes with lots of benefits such as price, long shelf life, ease of use in the pool, and for common household needs. 

While it does many great things, it still doesn’t pack the same punch as liquid chlorine or other chlorines and if you accidentally buy the wrong kind of bleach, you can do some pretty big damage to your water chemistry.

Our advice is to stick to swimming pool chlorine unless you know exactly what is in the bleach you buy.