When properly stored, pool chemicals generally have shelf lives of 3-5 years. Pool chlorine is no different, though certain forms of it are more stable and last longer than others. Keeping chlorine in environments that are consistently cool, dry and dark will extend the time they remain usable.
Tablet Chlorine
At 36 months, In The Swim tablets still have 98% of their original available chlorine, when stored in constant 50-70° F temps with a tightly closed bucket lid. In the right conditions, trichlor tablets can remain viable for more than 5 years.
SKIMMER NOTES: As a general rule, most pool chemicals, including pool shock and balancers, should be used within two pool seasons. BUT if you use chlorine and bromine oxidizers and sanitizers, it's best to use them within one season.
As pool chemicals age, their composition changes and they become less effective. Dry chemicals absorb moisture. In addition, exposure of any chemicals to sunlight or extreme cold or hot temperatures can have a significant impact on efficacy.
One of the biggest misconceptions, meanwhile, is that at-home pool chemicals can be stored in a garage. This should always be avoided, as chlorine can cause metal rusting, while garages are poorly ventilated and can therefore lead to an unhealthy buildup of toxic fumes.
Liquid Chlorine has the shortest shelf life of all your pool chemicals, losing up to 50% or half of its potency six months from when it was first opened and up to 90% after a year.
The best way to store chlorine tablets is in a cool, dry, well-ventilated area, away from direct sunlight and extreme temperatures.
The best way to dispose of these materials and their containers is through Household Hazardous Waste (HHW) programs or facilities.
Method #1: Floating dispenser
Another way of adding chlorine tablets to your pool is with a Small Floating Tablet Dispenser. This can fit 3 x 200 g tablets and provide controlled release of chlorine over five days.
Too much chlorine in your pool can cause skin and eye irritation as well as damaging your pool equipment and affecting your water's pH levels.
It's not a good idea to just toss them in. Instead, you can use an automatic pool chlorinator that allows you to add just the right amount of chlorine at a time. You can also put a chlorine tablet in the skimmer basket while cycling your water. You can also rely on a floating chlorine dispenser.
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. Without tabs, the chlorine shock will dissipate quickly out of the water; without shock, the chlorine level will not get high enough to fully sanitize the water.
It is recommended to wait at least 20 minutes to an hour after adding water balancing chemicals. You should wait 2–4 hours (or one full cycle through the filter) to swim from the moment you use calcium chloride in your pool. It is safe to swim once your chlorine levels are around 5 ppm or after 24 hours.
Chlorine is very volatile in water and will eventually evaporate, hence why you can let it stand for up to 24 hours. But if you raise the temperature of the water, you can speed the process of evaporation up and instead of 24 hours it should only take 15-20 minutes.
Most reagents from major manufacturers like Taylor and LaMotte will have an expiration date printed on the label. The expiration date is critical to avoid chemicals past their shelf-life that can provide inaccurate test results.
Do Chlorine Tablets Go Bad? The simple answer to this question is yes. Like any chemicals, chlorine tablets go bad if left long enough or improperly stored. Kept in the right conditions, however, and they can remain effective for over five years.
Unopened containers of chlorine granules or tablets, for example, can remain effective for about two to three years if stored in a cool, dry, and well-ventilated area.
To handle chlorine tablets safely, it is important to always wear protective gear such as gloves, goggles, and a mask. Be very careful to never allow the chlorine tablets to directly touch your skin. By taking the proper precautions, you can help keep yourself and your family safe.
Liquid Chlorine has by far the shortest shelf life, losing 50% potency within the first 6 months and 90% within a year. So, if you have liquid chlorine from last season, safe to say it is no longer effective.
It is essential to regulate chlorine levels in a pool between 1-3 ppm, as levels exceeding 5 ppm can be hazardous. Swimming in a pool with high chlorine levels should be avoided. The highest safe chlorine level for a pool is 3 ppm.
Is chlorinated water safe to drink? Yes. The U.S. Environmental Protection Agency (EPA) limits the amount of chlorine in drinking water to levels that are safe for human consumption. The levels of chlorine used for drinking water disinfection are unlikely to cause long-term health effects.
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.
Suitable Storage Locations: Sometimes, outdoor storage for your pool chemicals is your only option. If this is the case, choose a location that's well-ventilated and away from direct sunlight. A shaded area beneath a sturdy awning or a pool shed can be an excellent choice for storing pool chemicals.