Shock is chlorine, in a high dose, meant to shock your pool and raise the chlorine level quickly. Chlorine tabs (placed in a chlorinator, floater, or skimmer basket) maintain a chlorine residual in the water. You do need to use both tabs and shock.
SKIMMER NOTES: No. Chlorine and shock are not the same thing.
Shock has a more intense chemical strength than the traditional chlorine sanitizers, and it also differs in how you should apply it to your swimming pool. Short answer: No. Chlorine sanitizers and shock are similar but different in strength.
Liquid chlorine and granular shock have the same active chemical that sanitizes your pool, what changes is the strength and the way you use it. Liquid chlorine is less costly, unstabilized and comes in liquid form. Granular shock is stabilized and comes in a solid form that dissolves in your pool.
Similarities Between Liquid Chlorine & Powdered Shock
Similarly, both forms have a higher concentration of available chlorine than those used in daily chlorination. They also both kill nearly all living microorganisms, bacteria and contaminants with ease.
Shocking will restore the proper chlorine level and restore water clarity. Both available in various forms: Chlorine comes in liquid, dissolvable granules, and granule pucks/tablets for slow-release. While shock is more fast-acting, it's also available in both granule (most common) and liquid forms.
It Should Not Be Done Together
This is because when you mix chlorine and algaecide together, it renders both of them useless. Hence, you should first shock the pool and wait for the chlorine levels to fall below 5 PPM.
How Often Should I Shock My Pool? Shocking your pool regularly will help to keep the water clean and free of contaminants. You should aim to shock your pool about once a week, with the additional shock after heavy use. Some tell-tale signs that your pool needs to be shocked are cloudy, foamy, green, or odourous water.
Swimming pool shock contains 12.5% sodium hypochlorite (bleach) vs. 6-8.5% for Clorox (bleach). Some Clorox products go as high as 8.5%. At a 12.5% concentrate, liquid pool shock is approximately 2x's stronger than Clorox bleach.
"Shocking” refers to the process of adding chlorine or non-chlorine pool chemicals to the water in order to raise the "free chlorine” level. The goal is to raise this level to a point where contaminants such as algae, chloramines and bacteria are destroyed.
After Shocking Your Pool
It is safe to swim once your chlorine levels are around 5 ppm or after 24 hours. It is always best to test first!
Common unscented household bleach (sodium hypochlorite) works well to shock a pool.
A pool filter should be run for a minimum of 6 hours after shocking a swimming pool. This is to allow the filter to clean the water and give the shock enough time to fully mix with the pool water. Running the filter after shocking for 24 hours to 7 days is necessary if the pool has a large amount of algae.
Can you put too much shock in a pool? SKIMMER NOTES: It's unlikely but it could happen. It would take a lot of shock to really make the water unsafe for swimming. The best way to make sure you're safe to swim is to test your pool water and make sure free chlorine levels are between 1-4ppm for healthy swimming.
Give the shock a good 12 to 24 hours to work it's magic. If the algae hasn't cleared up after 24-48 hours, clean and brush the pool and add another shock treatment.
Short answer: yes. Longer answer: it depends on the formulation. The label on every bleach bottle should tell you the ratio of sodium hypochlorite (and available chlorine) in the bottle to everything else. A higher percentage is generally better, as you'll need to use less bleach to treat your pool.
Shocking your pool isn't necessary, although, it's not a bad idea either. If you get an extremely heavy rain fall, you could shock your pool for good measure. This will help fight off any contaminants that the rain may have brought to your pool.
Although it's generally recommended that all the pool water undergo filtration every 24 hours, the pump does not need to run all the time. A proactive, productive and energy-saving maintenance activity is to remove the debris floating on the pool surface with a hand-held skimmer.
Sun Down – You'll want to shock your pool in the evening when the sun has gone down. This gives your pool plenty of time during the night to free the chlorine and clean the water. In the morning, you should be able to enjoy your pool. If you shock your pool during the day, the sun's UV rays will dissolve the chlorine.
Why do you need to shock a pool? Pools are shocked to remove combined chlorine molecules, aka chloramines from the water. Pools are also shocked to remove excess bather waste and bacteria after heavy pool use, contamination events, or for the removal of visible algae in the water.
Perhaps most important note of all, never add chlorine and muriatic acid together in the pool. This creates a dangerous toxic gas that can have severe health consequences if inhaled.
Brown pool water is often caused by metals (iron) becoming oxidized in the pool water. If you shocked your pool water and it turned brown you probably have metals. Oxidized iron usually turns a brown or rusty color in the water.
Algae will remain in your pool after shock if you've had insufficient chlorine and an overabundance of metal elements in the pool water. Therefore, to start the cleaning process. Remove all the debris from the pool with a leaf net and then let the smaller dirt fragments settle.
You cannot overshock a swimming pool or add too much. Adding too much shock or overshocking your pool will kill off algae. The negative of adding too much shock is it will upset the chemical balance of your pool.
Never close the cover immediately after shocking the pool. It is recommended to wait several hours before closing the cover. Use a test kit to regularly test the pool water. If the tests results are good, this does not imply the water chemistry was good prior to your current test results.