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.
The best time of day to shock your pool is in the evening. This is because the sun's rays can affect the effectiveness of the chlorine by dissolving it too quickly, before it has a chance to rid the pool of contaminants and clean the water.
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.
If the pool is still very cloudy or green, you may need to shock it to make it safe to swim in again. First, make sure that the filter system is working properly and the chemicals are still at the proper levels. Next, mix up your chlorine shock (hyperchlorinate) treatment.
It's pretty tough to over-shock your pool; shocking your pool two days in a row with the proper dosage for your pool volume shouldn't be a problem – and in fact, is sometimes even needed to rid your pool of algae and other contaminants.
To be on the safe side, you may also consider shocking your pool every 1-2 weeks as a preventative measure. If you're utilizing a saltwater system with your swimming pool, it's also a good idea to periodically shock your swimming pool if the chlorine levels are low.
Although, if you overdo the shock treatment, you risk getting green hair from chlorine due to the excess chlorine oxidizing the copper in the water. You can execute a shock treatment with a few different types of pool shock, just be mindful of how much you're using.
It is recommended that chlorine be added at the end of the day once the sun has set and there are no more bathers in the pool.
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!
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.
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. Only then should you introduce algaecide to get the best results.
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.
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.
When diluting, always add the chemical to the dilution water to prevent splash out of the chemical. Liquid chlorine is not stabilized and will burn off quickly in sunlight. Therefore, it should be administered in the evening, after the sun has set.
Pools can immediately turn green after shocking when they have metals like copper in the water. These metals oxidise when exposed to high levels of chlorine which makes the pool water turn green. Adding a metal control product such as Zodiac Metal Remover will help to restore the pool water.
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.
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.
In this case, you should double shock your swimming pool water. To double shock, you will need to add 2 pounds for every 10,000 gallons of water. For instance, if you pool is 20,000 gallons, you will add 4 pounds of shock.
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.
Properly stored chlorine tablets should last three to five years. The storage site should be cool, dry and well-ventilated, such as in a basement. Never leave chlorine tablets in the direct sun, even in a covered bucket, because the heat will accelerate the degrading process of the tablet and its ingredients.
All pool chemicals, aside from unstabilised liquid chlorine, are good for up to three to five years as long as they're stored in a cool and dark place away from sunlight and they're packed in air-tight containers.
Liquid pool chemicals, on the other hand, tend to have a shorter shelf life. For example, dry pool chlorine will not expire for a long time, while liquid pool chlorine will expire quickly. If you have any pool chemicals in liquid form, they will only last up to two months before they begin to become ineffective.
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.