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.
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.
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.
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.
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.
Low chlorine levels often cause green or hazy water, so if your water looks a little cloudy and you haven't shocked in a while, adding shock is the first step.
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!
"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.
However, it's important to note that you can't shock your pool with regular chlorine tablets. While pool shock is usually made from chlorine, pool shock chemicals are much more highly concentrated. Proper shock treatments are designed to literally “shock” your pool and raise the chlorine level quickly.
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.
There are four main types of pool shock: calcium hypochlorite, sodium hypochlorite, sodium dichloro-s-triazinetrione, and potassium monopersulfate. Calcium hypochlorite is the most commonly used pool shock with a typical chlorine level of between 50 to 80 percent.
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.
The cold water, anything below 65°, has an impact on the ability of the chemicals to dissolve properly. I would recommend using liquid chlorine if you have to shock in lower temperatures. You can dissolve granular shock in warm water. Perhaps it will work if you completely dissolve it before adding it to the pool.
Common unscented household bleach (sodium hypochlorite) works well to shock a pool.
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.
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.
Shock-chlorination is an essential and effective method of cleaning the pool. But you need to have the pump circulating the water for this to be effective.
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.
BUT, if you have to shock your pool during the day in broad daylight, you can still swim after adding shock. It's recommended that you wait one hour after adding shock with the filter running, and then test the water to confirm the pH and chlorine are in the proper range before letting anyone enter the pool.
75 ounces per 3,000 gallons every week. Initially you will need stabilizer to protect the chlorine from the sun. This is added at a rate of one pound per 3,000 gallons of water.
Chlorine issues often cause cloudy water. Adding a recommended dose of pool 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.
Heavy shocking with granular chlorine will generally require 24-48 hours before the chlorine level has dropped to safe swimming levels (below 5 ppm). Lithium and Non-Chlorine shock labels typically allow immediate swimming, but check the package label, to be sure.
Wait until the chlorine level in the water drops down to 1-4 parts per million (ppm) before allowing swimmers back into the pool. If the water still looks a little cloudy after the shock treatment, you may want to use a water clarifier before allowing swimmers back into the pool.
You do not need as much pool shock during winter as you normally would to achieve the same effect. The National Institutes of Health found that at normal summer water temperatures, the efficacy of chlorine was 2-3 times less than for water temperatures around 50 degrees.