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.
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.
Chlorine has a low pH level, and in order to maintain your pool water's clarity and balance, shocking weekly will allow you to quickly raise the chlorine level, which will rid the pool of contaminants, without lowering the water's pH levels.
If the water is clean and clear, then add about 3 oz of liquid chlorine per 1000 gallons of water – while the pool filter is running. This should give you a chlorine level of about 3 ppm.
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.
How long does chlorine take to work? One potential drawback for using chlorine as a disinfectant is that it takes time to kill bacteria. In water supplies, if the water is at 18°C or above, the chlorine will need to be in contact with it for at least 30 minutes.
Liquid chlorine is not stabilized and will burn off quickly in sunlight. Therefore, it should be administered in the evening, after the sun has set. Hold jug of liquid chlorine as far away from your body and as far into the pool as is comfortable and safe.
The procedure for adding granular chlorine is pretty much the same as adding calcium chloride or sodium bicarb to a pool. Measure the dry chemical, pre-dissolve in a bucket, and pour around the perimeter of the pool (never into the skimmer directly).
A pool should have a chlorine level between two and four parts per million (ppm). Make sure your above ground pool has enough by testing your water about every other day with chlorine test strips, such as these Aqua Chek Test Strips. Learn more about maintaining your pool's chemicals.
Sodium hypochlorite (also known as liquid chlorine) is another frequently used option for shocking pool water. This is a common choice in pool shock because you can pour the solution directly into the pool without having to dissolve the chlorine in water beforehand.
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.
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.
Excess chlorine can alter the pH level of the water in the pool, making it more acidic. The acid levels can cause any of the following symptoms: Irritant dermatitis which is a red skin rash characterized by raised itchy red bumps. Eye irritation and over-dilated blood vessels in the eyes.
Using liquid chlorine raises the pH of the water.
Liquid chlorine does not raise pH. When added to water, liquid chlorine (which has a pH of 13) makes HOCl (hypochlorous acid – the killing form of chlorine) and NaOH (sodium hydroxide), which raises pH.
It's often recommended to shock your pool once a week. If you don't do it every week, you should at least do it every other week. This is necessary to maintain your pool's water chemistry.
Once the pool is opened and the floor and walls have been brushed the first chemical you should add is chlorine to shock it. It's recommended you add a gallon of liquid chlorine or pound of granular chlorine for every 5,000 gallons of water in the pool. You can also add more chlorine at the end of the opening process.
This level is ideal for swimmers because it isn't so high that it burns the eyes or skin yet helps keep the pool clean. This pH range works well with floating chlorine dispensers.
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.
INITIAL STARTING DOSAGES :
Maintain chlorine at a minimum of 1.5 ppm and up to 3 ppm. The more swimmers you have and the warmer the water is, can double your pool's chlorine consumption. Add whatever amount of chlorine it takes to maintain a 1.5 ppm chlorine..
Chlorine is a chemical that inhibits bacterial growth in water. It's used to disinfect swimming pools and drinking water and sanitize sewage and industrial waste. It's also an active ingredient in several cleaning products. Chlorine poisoning can occur when you touch, swallow, or inhale chlorine.
Once you've added the chlorine, the walls and floor of the pool should be brushed to help kill off any algae and to mix the chlorine well with the water. If this step is missed, the chlorine will sink to the bottom of the pool, possibly damaging the liner.
Chlorine is heavier than water and will sink to the bottom if you don't slowly pour it into a return jet stream or brush the bottom after you add it. Once it is mixed in, it does not come out of suspension.
In the industry it is recognized to have the pool run for 3 hours at a bare minimum up to 24 hours. 24 hours really is overkill but it'll ensure the water is completely mixed with the chemicals.
It takes about 24 hours for the chemicals to properly circulate in order to get an effective reading from the retest. The water test will assess the pH, chlorine, total alkalinity and calcium hardness.