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.
Warmer air will cause the chlorine to evaporate more rapidly. If you decide to place the water in a jug that's left open in the refrigerator, the chlorine should evaporate completely within 24 hours. For quicker evaporation times, leave the water at room temperature.
In general, it's recommended that you wait up to 24 hours to hop into a pool after it's been shocked, depending on the size of the pool, Alan says.
Why Does Chlorine Lock Happen? The most common cause of chlorine lock is an overabundance of cyanuric acid (CYA). Cyanuric acid is commonly referred to as a "stabilizer" and is vital to maintaining healthy chlorine levels in your pool.
Generally after shocking your pool you should wait to swim at least 8-12 hours until chlorine levels come back to normal (1-3ppm). This is one of the few times that having a high chlorine level is a good thing. Always test your water before swimming again to make sure your chlorine levels are safe.
If your water's pH is too high, it hinders the chlorine's ability to efficiently clean the pool. A water pH level that is too low causes the chlorine to dissipate more quickly. Therefore you'll need to add more chlorine to accomplish the task.
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!
And how long do you have to wait before you can swim? You should wait one hour per pound of shock product added, and then test the water to confirm the pH and chlorine are in the proper range before letting anyone enter the pool.
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.
The Effects of Light
Hypochlorite breaks apart when ultraviolet radiation from the sun hits it, releasing the chlorine as gas into the atmosphere. Sunlight is so effective at reducing chlorine that a bright, sunny day can do so by 90 percent in just two hours.
What chlorine level is too high to swim? It depends on who you ask, but the acceptable range is between 1 to 5 ppm. (So, for example, 10 ppm chlorine is not safe to swim in — that's too high.)
Safe chlorine levels range between 1 and 3 parts per million. At concentrations above 6 ppm, the pool is unsafe.
Adding too much pool shock or putting too many chlorine tablets to the feeder can both result in very high levels of chlorine. Another common way to over-chlorinate a pool is to leave a liquid chlorine pump running all night – you'll often come in the next day to discover a greenish-looking 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.
If you shock your pool during the day, the sun's UV rays will dissolve the chlorine. Opening Day – Before the kids jump in for the new season, you should clean and shock your pool. Over the winter or during times of disuse, algae have a tendency to grow.
Typically for granular shock, you'll need one pound for every 10,000 to 13,500 gallons of pool water.
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.
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.
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.
The term, "Shocking” refers to the process of adding chlorine or non-chlorine chemicals to your pool in order to raise the "free chlorine” level to a point where contaminates such as algae, combined chlorine (also known as chloramines) and bacteria are destroyed.
If the chlorine smell is very strong, however, you may soon spot “red-eyed” swimmers emerging from the pool. That's when the pool water is assumed to have “too much chlorine” in it. Ironically, a strong chemical smell around the pool and “swimmer red eye” may be signs that there is not enough chlorine in the water.
Having too much chlorine in your pool water can be dangerous. Exposure to high levels of chlorine can cause lung irritation, skin and eye damage, and provoke asthma. Not only is it bad for your health, but it can be bad for your pool due to the increase in chlorine.
Long-term exposure to low levels of chlorine gas is potentially linked to diseases of the lung (bronchitis, shortness of breath, possible permanent damage) and tooth corrosion. No cancer or reproductive effects have been reported from chronic exposure to chlorine.
But excessive exposure to chlorine can cause sickness and injuries, including rashes, coughing, nose or throat pain, eye irritation and bouts of asthma, health experts warn. Instructions for safely chlorinating a pool usually call for a maximum of four parts per million when people are in the pool.