Pool Shock 101: What It Is, Why It Matters, and How to Use It—the Easy Way

I’m here to dispel a misunderstood reputation. If you’re reading this, chances are you’ve heard about chlorine. But how much do you know about its counterpart, pool shock? I’d bet it’s a lot less. In fact, some people even argue that pool shock isn’t even necessary for optimally clean water—perhaps because a lot of the work that it does is invisible to the naked eye.

But whether or not you need a microscope to see it, there’s no question that without pool shock, you compromise the sanitary conditions and overall safety of your pool. Pool shock does matter, and I’ll explain why—as well as how to choose the right pool shock for you, how much pool shock you actually need, and how to make sure it’s spread evenly across your water. So take a deep breath, open your mind, and get ready to dive in.

Sounds Electrifying! What is Pool Shock?

Basically, pool shock is an exciting term for oxidation. It’s technically a type of chlorine, but don’t let that fool you. Despite its categorization, it enacts a more specific function than simply sanitizing your pool water—though it does that, too.

Here are the facts: after a chlorine particle attacks and kills bacteria or another organic material in your pool, it creates what is called a chloramine. This is an inactive particle that floats along in your water until it can be broken apart. And the only way this happens? You guessed it: pool shock.

Pool shock is the only kind of jolt your pool should be getting. Keep it warm and relaxed with the Energy-Saving ComforTemp Pool Heat Pump. As customer Angela G. notes, “It runs great and looks impressive. A good value—even our electrician was impressed.”

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Why Do I Really Need Pool Shock? Sounds Like Effort.

Think of the last time you were near a really strong, chemical-smelling pool. Well, we have to pause there. Because contrary to what anyone might first think, that smell isn’t from chemicals at all—it’s from a lack of chemicals. That smell is chloramines! And not only do they smell bad, but they greatly reduce how well the chlorine you add to your pool works.

Without active chlorine, all the bacteria that prevents your pool from being clean and safe—some bacteria are pathogenic, after all—will continue life uninterrupted. Basically, that pool pump you run for the proper amount of time every day, the pipes that connect it to your pool, the sanitizing chemicals you add, the skimmers you clean out regularly... all of these actions which take time and money to keep your pool in shape are compromised. Are you with me now?

How Do I Find the Right Shock for My Pool (and My Wallet)?

There are four major types of pool shock, but my top recommendation is to use calcium hypochlorite, which is the most popular and for good reason: it’s effective, and it’s the most affordable shock on the market. Unfortunately, it’s usually pretty labor intensive—since it’s slower to break down, you generally have to pre-dissolve each pound in a five-pound bucket of water first. My solution? Skip that process entirely by using calcium hypochlorite that you can add directly to your pool, without pre-dissolving—and thank your lucky stars it exists!

how to use pool shock

What About For My Hot Tub? Do I Need to Shock That, Too?

Congratulations, you’re one of the fortunate among us with a hot tub. But calcium hypochlorite is not for you. This is because it’s unstabilized, meaning that it breaks down in heat like direct sunlight—and loses 95% of its effectiveness in a hot tub. But don’t think you’re in the clear: no matter what sanitizer you use, you still have to worry about chlorines (or, if you use bromide, what we call bromamines).

To shock your hot tub, you’ll want to use a stabilized shock like dichlor shock, which is also inexpensive and widely available. That is, unless you use two specific sanitizers: for a biguanide sanitizer, you’re better opting in for a biguanide shock, and for a spa mineral sanitizer, you’ll want non-chlorine shock.

All cleaning chemicals only spread evenly thanks to your pool pump. For thorough circulation, try the 1.5 HP Variable Speed Blue Torrent Thunder Pool Pump. It pays itself off in energy saved and includes a lifetime warranty. As customer Eric D. says, “For variable speeds, can’t find much better price than this. Day one, I fired this pump up and it ran clean and fast.”

Got My Shock. But How Much Do I Need?

As with any cleaning chemical, the amount of pool shock you use depends on the volume of your pool. Generally, the magic number is one pound per 10,000 gallons. This is especially easy to measure out when you buy pool shock conveniently packaged in one pound bags. Why not make your life easier?

Not sure how many gallons of water your pool contains? Simply multiply the length, width, and depth of your pool in feet, and then multiply that figure by 7.5 to convert the number to gallons. It’s a quick calculation anyone can do—even if you never exactly aced geometry. And if you think better in formulas, that would be:

[Pool Length in Feet] x [Pool Width in Feet] x [Pool Depth in Feet] x 7.5 = [Volume of Your Pool in Gallons]

When opening your pool for the season, you should use double the amount of shock to really clear out any bacteria, algae, and who-knows-what that’s built up in your water throughout the winter. That would be two pounds of pool shock per 10,000 gallons of water.

how to use pool shock

Can I Just Drop Pool Shock Right In?

As long as you have shock that doesn’t require pre-dissolving, adding pool shock to your pool is unbelievably easy. All you have to do is walk slowly around the perimeter of your pool and pour it straight in.

If you have a type of sodium hypochlorite that requires pre-dissolving, add each pound to a five pound bucket of water and give it a mix and some time before adding it to your pool.

In either case, if you have an outdoor pool remember to apply pool shock at dusk or at night, or the sun will burn out the compound that makes it effective. True to its name, pool shock for pools is usually unstabilized. If you’re adding pool shock to your hot tub, any time will do.

Unless you’re using a non-chlorine shock, you’ll want to wait eight hours after using shock before you jump back into the pool. If you’re a night swimmer, go you. Just add pool shock in after you’re done for the day.

Shocking your above-ground pool? Make sure it’s circulated properly with a high-powered pump like the Copper Force Above Ground Pool Pump, which has three options for horsepower and an ultra-cool operation. According to customer Doug Paar, “The pump is very quiet and has good pressure. I would recommend.”

how to use pool shock

Easy Enough! Now How Often Does My Pool Need to Be Shocked?

Throughout the season, I recommend you use pool shock once a week. Seems like a lot? Don’t sweat it—if you add it to your routine of basic pool maintenance, you’ll hit a flow comparable to the chemical circulation of your dreams.

Here’s to a Shockingly Fresh Swim

Congratulations, you’re now part of the club. Once you complete your first shock and feel the difference—after waiting eight hours, of course—there’s no going back, with the exception of a backstroke. Enjoy your next swim. Not only is it relaxing as ever, but now it’s all the more safe. And in the end, isn’t that really what matters most?


Related articles:

Ideal Schedule for Your Variable Speed Pool Pump

What To Do When Your Pool Pump Won’t Turn On?

How To Fix An Overheating Pool Pump?

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