When is it safe to go into a pool after it's shocked? 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.
After you shock the pool — As soon as your chlorine levels reach 5 ppm or lower, it's officially safe to swim. Depending on the type of shock used, as well as the amount used, it can take anywhere from 24 hours or even up to a couple of days.
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.
If you enter the pool immediately following a chlorine pool shock treatment, you are risking as little as skin and eye irritation and as much as fatality. Shocking your swimming pool is necessary, but take caution when doing so.
Wait about 20 minutes after adding balancing chemicals to your newly filled pool, and you should be good to swim. Calcium chloride – If you have hard water issues, it's advised to wait about 2-4 hours before swimming after adding calcium chloride to soften your pool's water—or until one filter cycle has been completed.
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.
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.
The Bottom Line about Pools and Chlorine
As mentioned above, you could probably swim in a pool without chlorine without any major health issues. However, long-term use of a pool lacking chlorinated H2O could make you sick or, at the very least, contribute to rashes and other types of skin irritation.
But is it safe to swim in a pool with algae? Whether mild or severe, it isn't recommended. Significant amounts of swimming pool algae welcome a breeding ground of harmful bacteria that feed on algae. These bacteria pose health risks to swimmers, most commonly resulting in a skin rash.
Milky pool water is not safe to swim in and can be caused by things such as poor water chemistry, improper filtration, or low sanitation levels. Milky pool water can be cleared up by cleaning your pool surfaces and filter as well as ensuring all chemicals are balanced properly.
Add Pool Water Clarifier
After your pool water has circulated and your shock has dissipated, it's time to add your clarifier. Clarifier helps bind tiny particles into bigger particles that your filter can capture.
Chlorine, either solid or liquid, is a pesticide used in pools to destroy germs, including those from feces, urine, saliva and other substances. 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.
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.
Thirdly, tripple-shock the pool using stronger Chlorine like In The Swim calcium hypochlorite (3pounds for 10k gallons) to kill all the algae; depending on the number of algae in the pool, it may take 2-3 days for the pool to clear up. The filter should run 24 hours a day for faster results.
Light Green or Teal Pool 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.
Proper chemical balance and sanitizer levels will prevent many opportunities for algae to bloom. High pH and low chlorine (or other sanitizer) can give algae a great start.
The slimy and often smelly film that floats on the water's surface is a distinct green color, so look carefully for it before going for a swim. If there's an off-smell, don't go for a swim and don't let your dog take a plunge either.
Generally speaking, the dosage amount of pool shock is 1 lb. per 10,000 gallons, but consult the shock package label.
Even from a health standpoint, it is simply not safe to operate a pool without some added “chemicals” to combat bacteria and contaminants in the water. A pool without chemicals is the perfect breeding ground for bacteria, viruses, and parasites.
While the quart or so of water that was setting in the hose may have some chemical contaminants in it, by the time that is diluted into thousands of gallons of water, it's of no concern. That is of course assuming that your swimming pool is not your primary source of all drinking water.
I think the answer to your question is about 3-6 days. The problem is that the chlorine that you need to keep the bacteria in check is used up more quickly as the temperature rises, the activity increases, and as sweat and other body stuff is put into the pool.