What Is Pool Shock And What Does It Mean To Shock Your Pool
The term pool shock refers to a super-concentrated dose of pool sanitizer. Pool shock treatments are usually sold in granular form, and you can find them at just about any pool supply store or big-box home improvement store. Swimming pool shock treatments are available in chlorine and non-chlorine/oxygen-based formulations.
When you shock your swimming pool, youre intentionally over-treating your water. The excess dose of chlorine kills off bacteria and neutralizes contaminants that might otherwise cloud your pool water or encourage the growth of algae or harmful bacteria.
Does Liquid Chlorine Raise Ph
A: No. It does not raise pH. When dissolved in water, liquid chlorine enables Hypochlorous acid and Sodium hydroxide , which helps the level rise. However, when the Hypochlorous is deflated by UV, it births hydrochloric acid . The rate of this HCl is almost the same as the amount of NaOH; therefore, any net effect on pH is nearly nothing or completely zero.
How Often Should I Shock My Swimming Pool
Pool Shock is a type of chemical used to destroy bacteria and other organic contaminants in your swimming pool.;Chlorine shock can be used to give your chlorine level a boost when it is very low. After using a chlorine-based;shock, you should wait at least 8 hours before going back into the pool.;Non-chlorine shock is a nice alternative and can be used as a supplement to your normal pool chemicals. With most non-chlorine shocks, you can swim again 15 minutes after shocking the water. Always make sure that the filter system is running while shocking the pool.
Some pool owners choose to shock their pools once every 1-2 weeks as normal maintenance. This is a great way to keep your chlorine level up and prevent algae growth.
In addition to your regular maintenance, common circumstances in which its a good idea to add shock to your pool water include:
Just remember At a minimum, be sure to shock your pool in any of the above situations. To be on the safe side, you may also consider shocking your pool every 1-2 weeks as a preventative measure. If youre utilizing a saltwater system with your swimming pool, its also a good idea to periodically shock your swimming pool if the chlorine levels are low.
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What Is A Pool Shock
Shocking your above ground pool is a necessary part of its maintenance routine. A shock simply refers to adding above normal levels of chlorine or sanitizer to your pool to quickly raise the levels of chemicals in a very short amount of time.
The reason for shocking a pool is to remove ineffective chlorine, kill bacteria, and get rid of algae. Additionally, youll be raising the level of effective chlorine and helping your pool get clean and safe to swim in again.
What youll need to shock your above ground pool:
- Pool cleaning supplies
- Pool shock mix/shock kit
How Much Liquid Chlorine Needed For 10000

It is generally recommended for any pool owner of a 10000-gallon pool to use a single pound of calcium hypo for its shocking. Also, sodium hypo of 10 ounces alongside approximately 12.5% chlorine is required to sanitize your pool.
While observing and executing all these, ensure the pool water is at its standard temperate level. Also, ensure the pools pH falls between 7.2 and 7.6 while maintaining its alkalinity between 80 and 120 ppm.
The maintenance level is not the same for a 10000-gallon pool, whether a chlorine-based pool or a saltwater pool. The chlorine-based pool requires more maintenance than the saltwater ones.;
Generally, whether for a 10000-gallon pool or whatever category of the pool, the saltwater pool does not need much treatment. The exception to this is an influx of algae or the contamination of the saltwater pool by soil, oil, or other liquid contaminants.
The reason for this is not far-fetched. Saltwater pools use chlorine generators to produce a chlorine compound, which is almost like the chlorine present in shock treatments.
Meanwhile, the best usage option regarding the saltwater pool system is the Sodium Hypochlorite liquid chlorine, as it helps to enhance chlorine levels in the pool water. You can use it in treating your hot tubs and spas as well.;
Once used in a hot tub or swimming pool, it is instantaneously ready to erase viruses, bacteria, algae, and any other microorganisms present within the water due to its quick and rapid action.
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How To Add A Mineral System To Your Pool
When it comes to pool sanitation systems, the two options people tend to think of first are traditional chlorine systems or saltwater systems. But what they often do not realize is that these are both chlorine systems, and both rely on having a free chlorine level in the 2-5 PPM range. The only difference is that in a salt water pool, the chlorine is “automatically” generated through a reaction between your salt chlorinator cell and the salt in the water, instead of by directly adding chlorine to the pool.
For those looking for an alternative requiring less chlorine, a mineral system offers quite a few benefits, such as:
- less “chlorine smell”
- less wear and tear on components
- less fading of liners and swimsuits
- and water that is usually deemed as “a lot more comfortable”
Unlike traditional chlorine or saltwater systems, mineral systems rely on a combination of minerals and a low level of chlorine to keep the pool water free from bacterial or other growth. Because of these added minerals doing work for you, a pool with a mineral system requires a much lower amount of free chlorine – generally in the 0.5-1.0 PPM range …that’s less than half the levels you’ll find in none mineral pools!
But how hard is it to add a mineral system? And how much will it cost?
The good news is mineral sanitation systems are both extremely easy to add, and relatively inexpensive .
How To Shock Your Pool
Shocking your pool isnt terribly complicated. If you can test and balance your water chemistry, you can shock your pool. Although the shock process can vary a bit, youll follow a few basic steps:
Safety first!
Pool shock treatments can irritate your skin and eyes, so take these safety precautions when using them:
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Shock Pool With Algae
You do not want to see the full extent of damage algae can cause to your swimming pool. The dull appearance and the astronomical drop in chlorine concentration within the pool become even quicker with algae.;
Algae consist of a wide range of eukaryotic, phototrophic, and oxygenic microorganisms that use energy and light as a source of growth. Algae is different from plants because; they do not possess any tissue differentiation.;
Any pool with algae is an eyesore and very much dangerous to health. That is why it is crucial to act fast whenever they are perceived to be within the swimming pool.
However, just a dose of fresh chlorine can eliminate this inimical threat to your pools survival.
These are the main types of algae: Blue-Green Algae , green pond algae, filamentous/string/hair algae, bryozoans, diatoms, red pond algae, chara/muskgrass, golden algae.
How Much Shock Do I Need To Shock My Pool
A simple ratio and a standard rule of thumb to follow when you shock your pool is to dissolve one pound of either calcium hypochlorite or sodium dichlor for every 10,000 gallons of pool water. If you are using sodium hypochlorite, i.e., liquid chlorine, the ratio comes out to 10 ounces for every 10,000 gallons of pool water.
If you are not sure how many gallons are in your pool, here is an easy formula:
Length of your pool x width x depth x 7.5 = volume in gallons
You can also use the Pool Volume Calculator that is built into the Pool Calculator App, available on the web, or as a Native App on iOS or Android
Another standard measurement point for shocking a pool is to measure the chlorine by parts per million . To successfully shock a pool, especially one with algae growth, youll need to bring the chlorine level to at least 30ppm.;
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Treating Your Hot Tub With Bromine
Bromine has the same disinfection qualities as chlorine. But its advantage over chlorine is that it is stable: insensitive to high temperatures, UV and pH variations.
In addition, bromine has less odour than chlorine and does not produce any by-products . Bromine is therefore very suitable for hot tub treatment. It should be noted that it is a little more expensive than chlorine.
NB: The bromine treatment can be completed with active oxygen which is a bromine activator. It regenerates the bromine consumed.
Chlorine-based products cannot be combined with bromine treatment . For a shock treatment , hydrogen peroxide is used.
Ensure Pump And Filter Are Running
During the shock treatment, and especially after, it is important to keep your pump and filter on and running. This will ensure that the added chlorine is evenly distributed throughout the entire pool to get rid of bacteria and algae in the pool water. Once the shock treatment has been completed, keep the pump and filter running for a few hours to circulate the water. This will clean up the remnants of the shock and disperse any remaining cloudiness.;
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You Didnt Use Pool Floc Or Clarifier
Pool flocculant and pool clarifier are very similar and using either one can help clear up cloudy green water.
Flocculant binds to small particle impurities in the water, causing them to clump together and fall to the bottom of the pool. Once there, they can be removed with a skimmer or vacuum.;
Clarifier works to clarify the water . In all seriousness, clarifier works exactly the same as floc, except the clumps float on the surface of the water, allowing you to use a skimmer to pick them up, or let the pools filtration system do its job.
Frequency Of Pool Shocking

The frequency of pool shocking depends highly on how much you use your pool. As a general rule of thumb, shocking every two weeks is considered good practice. Theres no harm in doing it every month or so but thats usually not recommended, especially if people are using your pool daily.
Besides shocking for regular maintenance and upkeep, there are other times when you should consider shocking your pool:
- ;;;When the water temperature rises above recommended levels
- ;;;After heavy rains
- ; ;When the free chlorine goes below recommended levels
- ;;;When the pool water is used frequently or heavily
- ;;;During extended periods of hot weather
Bottom Line
Keeping your pool in its best condition may seem like an arduous and time-consuming process, but all you need is regular pool maintenance. Shocking will help you to avoid bigger messes and headaches down the road. When it comes to shocking and when the best time of day to shock pool is, be sure to do it frequently, when the sun has set and ensure the pool is safe for swimming before jumping back in.
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When Should You Shock Your Pool
Its best to shock your pool once the sun goes down and when the pool filter is running. If you put the shock in while its sunny out, it will not work as well. Never shock your pool when people are swimming in it. This is extremely dangerous. By waiting until the filter is running, you can be sure that the shock is filtered properly all around your pool.
You Didnt Shock Properly
Did you shock the pool with the proper amount of shock?;
Its pretty hard to screw up shocking a pool, but if your calculations are wrong, you may have under-shocked the pool.
Keep in mind that green pools usually need a few rounds of shocking to get them back under control. Shock dosages are usually 1 bag per 10,000 gallons of pool water.
Its recommended to use granular calcium hypochlorite shock, or a large dose of sodium hypochlorite if thats your chlorine of choice.
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What Happens When You Swim In A Shocked Pool
For pools that have added 1lb per 10,000 gallons and a person swims within 24hrs the bather would become very uncomfortable very quickly. It will cause the eyes to burn and the skin to feel dry, and after getting out will smell chlorine for a while.
For people who swim in a pool that has over 3lbs per 10,000 gallons within the first 48 hrs may experience the same discomforts from above but may be more intense.
In either case an accidental swim in a shocked pool is not life threatening for humans or pets, but extended periods of time may pose a real health risk.
How To Tell If Your Pool Has Too Much Chlorine
The chlorine in your pool is made up of two types of chlorine compounds. Free chlorine is the âgoodâ type of chlorine that is still available to eliminate bacteria and microorganisms. Combined chlorine, also known as chloramines, is what happens after the chlorine has combined with organic matter and is responsible for the characteristic smell associated with chlorinated pools.
Contrary to popular belief, you cannot smell how much chlorine is in your pool. Dry hair, sensitive skin and irritated eyes are all indicators of an over-chlorinated pool, but there is a less inconvenient and safer way to find out whether your pool has too much chlorine.
A DPD testing kit measures free and combined chlorine levels to give a total chlorine count. You could also use an OTO kit, but this only measures the free chlorine available in your pool. These types of titration tests are the most accurate method for determining the chlorine levels in your pool and help you better assess how to lower the chlorine levels in your pool if necessary.
To use the DPD testing kit, measure out a small amount of pool water and add buffered DPD powder to the water, which turns pink. Next, add a specialized FAS compound one drop at a time until the water transforms from pink to clear. Each drop of FAS compound is equivalent to 0.2 ppm of chlorine.
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Balance Your Pool Chemicals
Once the water is thoroughly clean, test it for alkaline, pH, and chlorine levels using a test kit. You can buy them online or take a sample to the local pool store for analysis.
Adjust chemicals like muriatic acid, while using chlorine stabilizer to protect your current level of chlorine. Keep the recommended chemical balances for swimming pools are as follows:
- pH: 7.4 7.6
- Chlorine: 1.0 3.0 ppm
- Total Dissolved Solids: 500 5000 ppm
What Happens If Ph Is Too Low In Pool
Low pH water will cause etching and deterioration of plaster, grout, stone, concrete and tiling. Any vinyl surfaces will also become brittle, which increases risk of cracks and tears. All of these dissolved minerals will hold in the solution of your pool water; which can result in staining and cloudy pool water.
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Cleaning Your Above Ground Pool Before The Shock
In order to apply a pool shock to its maximum effectiveness, youll need to make sure your above ground pool is completely clean. Run your vacuum as you brush the sides and skim the top of the water. Chlorine works to neutralize organic matter and bacteria the more you can remove before hand, the more effective the shock will be on the stuff you cant see like algae, skin cells, oils, etc. Nasty, I know!
When Should You Shock Your Pool And How Often

These are probably the two most common questions that swimming pool owners have about pool shock. And, like many pool-related questions, theres no single right answer.
The short, simple answer to both questions is, it depends on several factors, like how much you use your pool and if it has been exposed to any contaminants. The guidelines below should help you decide when to shock your pool:
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Consider The Nuclear Option
Unfortunately in some cases of green water, the pool can be too far gone to bring back to life and youll have to do a partial or full drain. But, as filling a pool skyrockets your water bill, this should always be a last resort.;
If you can still see the floor in the shallow end of the pool, it may have a fighting chance. Run the filter non-stop, brush and shock like theres no tomorrow, and endlessly test and balance your water.
However, you also have to consider if your pool filter can handle the job. If its on the smaller side, gets overwhelmed by thick water, or is too noisy to run 24 hours a day, you may have to throw in the towel.
Additionally, stains from algae and other debris can be permanent on the pools finish. While you may be able to get rid of the green water color, the stains might have to be acid washed, which will require a full drain.