The percentage of available chlorine is quite low for pool bleach, 12.5% is standard. Household bleach, by contrast is typically a more diluted 5 or 6% solution of the same sodium hypochlorite solution.
Regardless of how frequently or what system you use to add chlorine to the water, the chlorine level should stay between 1.0 and 3.0 parts per million (ppm) to maintain a healthy pool.
Calcium hypochlorite is the most commonly used pool shock with a typical chlorine level of between 50 to 80 percent.
For every person who uses the pool each day, you will require a further 10 grams of chlorine. Example – A 50,000 litre pool will require up to 200 grams of chlorine and if 5 people use the pool a further 50 grams of chlorine is required = total of 250 grams per day.
To superchlorinate, add AT LEAST 2.5 ounces (5 tablespoons, 75 grams) of chlorine for every 100 gallons (400 litres) of spa water or part thereof. Adding more is fine and never a bad idea.
The recommended concentration for disinfection has been 600-800 ppm of chlorine bleach and 50 to 200 parts per million (ppm) for sanitizing.
If chlorine is used, the free residual chlorine concentration in your pool should be maintained at 1.0 to 3.0 mg/L. The ideal level is 2 mg/L. When a pool is not in use, a method such as a floating immersion dispenser should be used to disinfect the pool water at all times.
Shock is liquid or granular chlorine. You should add one gallon (or one pound) of shock per 10,000 gallons of pool water every week to two weeks. During hot weather or frequent use, you may need to shock more frequently.
2 ppm of Chlorine will take up to 4 and a half days or around 110 hours to evaporate from 10 gallons of standing water. Ultraviolet light, water circulation, and aeration will speed up the evaporation process dramatically. Chlorine will last between 6 and 8 minutes in 10 gallons of boiling tap water.
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.
Aim to maintain a chlorine level of 3 to 5mg/l at all times. How frequently you add more chlorine will depend on your usage and bathing habits. It could be daily, every two to three days or weekly. For 1mg/l, add 2g per 1000 litres.
To dose water in a tank with 5 mg/L chlorine use: 40 millilitres of liquid pool chlorine or 170 millilitres of bleach, for every 1000 litres in the tank. Always test the residual chlorine level with a chlorine test strip.
Chlorine is added to the water to kill germs. But it does not work right away. If used properly, free chlorine* can kill most germs within a few minutes. CDC recommends pH 7.2–7.8 and a free chlorine concentration of at least 1 ppm in pools and at least 3 ppm in hot tubs/spas.
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.
The standard solution for a bleach and water sanitizing mix is one teaspoon bleach to one gallon of water or 1/4 teaspoon bleach to one quart of water (in a spray bottle). This is based on concentrated household bleach containing 8.25% sodium hypochlorite.
A solution of bleach and water should be used to sanitize all food preparation and contact surfaces. 1 tablespoon of bleach per 1 gallon of water will give you a 50-200 ppm sanitizing solution. This can be used to sanitize dishes, utensils, food preparation counters and tables.
The ideal level of free chlorine in the swimming pool is 2 to 4 ppm. 1 to 5 ppm is acceptable and 9 ppm is on the high side. 9 ppm would likely be safe to swim, but could be more of an irritant. Ideally, the level would be alllowed to come down to 5 ppm before swimmers are allowed to swim.
While a floater does not distribute chlorine as evenly as an in-line chlorinator, it is still a great form of swimming pool chlorination. Never put chlorine tablets into the skimmer baskets of your pool.
What are safe levels of chlorine in drinking water? Chlorine levels up to 4 milligrams per liter (mg/L or 4 parts per million (ppm)) are considered safe in drinking water . At this level, harmful health effects are unlikely to occur.
65% - You will need 16g by weight or 15ml by volume of cal-hypo 65% to raise your pool chlorine levels by 1PPM per 10,000 liters of water. 75% - You will need 14g by weight or 13ml by volume of cal-hypo 73% to raise your pool chlorine levels by 1PPM per 10,000 liters of water.
Find out the volume of your pool. This will give you an idea of how much shock you need. The general recommendation is to use 1 pound of cal hypo shock for every 10,000 gallons of pool water, and 10 ounces of sodium hypo with around 12.5% chlorine to sanitize your pool. Make sure the pool water is at its normal level.
For the greatest protection against algae, bacteria, and cloudy water, Intex pools should maintain a chlorine level of 2.0-4.0 ppm at all times. If you opted for the Intex Salt Chlorinator, you can make your own chlorine by adding the correct amount of Pool Salt to the water.
You can swim with chlorine tablets in the pool if the chlorine tablets are in a container. Getting in touch with those tablets can cause rashes, irritation and eye problems. However, to be in a safe zone it will be better if you wait for 3 to 5 hours till the chlorine levels touch 4 to 6 ppm.