It's recommended that you should do a pool shock once a week. The more you use the pool, the more often you need to shock it. Occasionally, you may need to perform an extra pool shock after: Heavy pool use, like a pool party.
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.
The ideal time to shock your pool is in the evening after all swimming is complete. In the evening because the sun will not be boiling the chlorine out of your pool, and after everyone is done swimming because shocking is going to bring the chlorine level up to a level that may be irritating to skin and eyes.
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. Without tabs, the chlorine shock will dissipate quickly out of the water; without shock, the chlorine level will not get high enough to fully sanitize the water.
Are chlorine and shock the same thing? 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.
After Shocking Your Pool
It is safe to swim once your chlorine levels are around 5 ppm or after 24 hours.
Adding a recommended dose of shock to your pool can clear it right up. Poor circulation or filtration can contribute to cloudy water. Make sure your pump and filter are working properly.
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.
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.
It's often recommended to shock your pool once a week. If you don't do it every week, you should at least do it every other week. This is necessary to maintain your pool's water chemistry. If you have a lot of people over in your pool or have a party, you may want to shock your pool more frequently.
What happens if too much shock is added? 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.
The best time of day to shock pool is when the sun is down. So, experts recommend shocking your pool in the evening or at night, to make sure it does its job. Shocking during the day can be ineffective as UV rays from direct sunlight significantly reduce free chlorine levels.
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.
So if you buy liquid shock, be aware that it only lasts one to two months at the most before it starts to lose effectiveness. While many swimming pool chemicals stay good for years if stored correctly, some pool-maintenance supplies expire more quickly.
At chlorine levels over 10 ppm, swimsuits can begin to fade. Pool covers become damaged, and the water is generally uncomfortable and unsafe for swimmers. Close the pool and keep covers off until chlorine levels fall back below 5.0 ppm.
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.
You can also simply add more chlorine, and pouring household bleach into the pool is one way to do this. Be sure the pH is in the proper range -- between 7.2 and 7.8 -- and add the bleach in the early evening to avoid having most of it degraded by sunlight.
Super chlorinate (shock) the pool ideally with liquid chlorine to shock level to 20ppm of Free Chlorine using either Liquid Chlorine (1.5L per 10,000L) or Chlorine Granules (310g per 10,000L). Run the filtration system on 'Recirculate” for 1 hour to allow the chlorine to spread throughout the pool.
The shocking agent, typically a non-chlorine oxidizer, breaks down the chloramines so that they can help in the sanitizing process. Basically, it becomes chlorine again. There are two types of shocking agents — chlorine and non-chlorine. Most non-chlorine shocks are labeled as oxidizer, a nod to the chemical reaction.
But if the cloudy water persists long after you've shocked the pool, you're likely having an issue with water balance, circulation, or filtration. Heavy use of a calcium based pool shock (cal-hypo) may increase Calcium Hardness over a period of time, increasing your odds of cloudy water.
High doses of chlorine, like pool shock, can cause temporary cloudiness as it kills contaminants. High levels of pH, alkalinity, and calcium hardness are more likely to cause cloudy water.
Cloudy or milky water after shocking is normal, and the water should clear up within an hour or so. Just make sure your pump and filter are running properly. If you add algaecide, keep in mind that some algaecide contains copper, which can actually make a pool cloudy.
Heavy shocking with granular chlorine will generally require 24-48 hours before the chlorine level has dropped to safe swimming levels (below 5 ppm).