The Complete Guide to Shocking Your Swimming Pool
Shocking your swimming pool is a crucial part of pool care, and as a pool owner, you really need to know how to do this in order to keep the water clean and algae-free.
But before you throw your hard-earned money away on a professional, check out our guide here to see how easy it is to do it yourself.
It may take a little time out of your day, but once you get the hang of it, you’ll be a pro yourself in no time.
What is Pool Shock?
The process of shocking your pool is simply super-chlorinating it for a specified period of time in order to kill anything floating around that doesn’t belong.
Certain algae, germs and debris can only be completely eradicated with the shocking process.
What the industry calls pool shock is simply the product you use to get the job done.
Why You Need to Shock Your Pool
Certain living organisms can still survive in your pool with its normal chlorine amounts. Others can become completely immune to it.
There are basically three reasons to shock your pool:
Sunshine breaks down your chlorine, causing it to lose up to 5 ppm per day.
Swimmers are constantly bringing in contaminants like makeup, sweat and bacteria that normal chlorine levels can’t always fight.
When to Shock Your Pool
Most people only decide to shock their swimming pools when they see an overgrowth of algae or the water starts getting cloudy, but by this time, cleaning your pool could take a lot more work.
So if you stay on top of this chore by shocking your pool once a week, you may be able to avoid an algae overgrowth.
This kind of contamination often requires way more scrubbing, vacuuming and sometimes even draining than you will ever want to do.
BUT…in case you are like the rest of us and occasionally put things off, here are the times when you should shock your pool even if you don’t feel like it:
Types of Pool Shock
There are several different types of pool shock on the market and it’s important to know the difference before you decide which one is right for you.
Calcium hypochlorite is usually granular and also sometimes called cal-hypo shock.
- 24 x 1 pound bags
- Powerful and effective chlorinated shock treatment
According to American Chemistry Council, it “destroys germs that are capable of causing numerous health problems for pool users--diarrhea, swimmer's ear (a nasty earache) and various respiratory, skin and wound infections.”
This is the most popular shock purchased because it’s considered the strongest and it’s also the cheapest.
It dissolves quickly and should be used at night because it’s adversely affected by sunlight.
Lithium hypochlorite is usually used in pools with high calcium levels because it doesn’t contain calcium itself.
It also does not have to be pre-dissolved making it slightly more convenient than other shocks.
This is a granular shock that dissolves slowly, so it’s cleaning power lasts longer than cal-hypo.
- Dichlor pool shock
- Will not cause scale build up
It’s another highly popular pool shock because of its availability.
This one is oxygen-based instead of chlorine-based, and it oxidizes the water and boost chlorine levels.
- Powerful oxidizing agent burns off dead chlorine cells and provides higher free chlorine levels
- Chlorine-Free shock oxidizes and eliminates algae growth and harmful bacteria
People can actually swim very soon after this treatment is applied so it’s a popular shock to use in between super-chlorinating during heavy swim times.
How to Shock Your Pool in 5 Steps
Now that you know all the facts about what it is and why it’s important, it’s time to get down to business and get this job done.
Pool shock can harm your skin and bleach your clothing, so make sure you wear clothes you don’t mind ruining, gloves and protective eyewear.
Prepare the Chemicals
Once you’ve chosen your pool shock, you will need to read the manufacturer’s instructions and prepare it accordingly.
For example, granular shock will usually need to be dissolved in a five-gallon bucket of water before it’s poured into the pool.
But other shock, such as lithium hypochlorite can be poured straight in.
You'll also need to determine the proper amount of shock to use with your particular size of pool and prepare it accordingly.
Shock the Pool
Poor the shock and water solution into the pool according to the manufacturer’s instructions.
Some will recommend you disperse it evenly around the edges and others will tell you to pour it in close to the jets to circulate it.
Leave it Alone
Leave the shock in the water to do its work.
The manufacturer’s instructions are important here as well to make sure no one gets in the water too soon after treatment.
It’s usually recommended that you leave it overnight.
Check Your Pool Chemistry
After you’ve waited the recommended number of hours, you still need to test your pool’s chlorine levels before letting anyone swim.
Make sure the levels have returned to normal before you allow anyone in.
Frequently Asked Questions
Shocking the pool can be a little intimidating at first, so here’s some answers to the most frequently asked questions:
What's the Best Time of Day to Shock?
Most pool shocks are best used at night so that the sunlight doesn’t decrease its effectiveness.
It’s also best to shock at night so that it can be left alone for several hours, giving it time to work.
How Long Does it Take to Shock a Pool?
The actual process shouldn’t take more than an hour, but depending on the product used, it could be up to 8 hours before you can use it.
How Long After Shocking Is It Okay to Swim In?
When using a chlorinated shock such as di-chlor or cal-hypo, you will need to wait the recommended amount of time before swimming, usually overnight.
When using a non-chlorinated product, however, it’s usually safe to swim after about 15 minutes.
Nobody likes a dirty pool.
Take it from me—if you shock your pool once a week, it will save you HOURS of cleaning time in the long-run.
Killing algae spores and bacteria before they spread is the number one way to stay ahead of pesky pool maintenance tasks once and for all. So, don’t neglect it.
Shock your pool on Monday and enjoy it the rest of the week!