How to Raise Chlorine & Bromine in a Pool

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Different types of "shock" chemicals are available, come of which don't use chlorine.

All of the chemicals and equipment you'll need will be available at a local pool supply store.


Always wait at least eight hours after shocking the pool to go swimming. Leave the pool uncovered after you shock it, or else dangerous fumes released by the shock chemicals will get trapped under the pool cover.

Keep your pool clean and clear with chlorine or bromine.

Everyone knows the smell of chlorine from trips to the public pool. Chlorine is a powerful disinfectant, used to keep bacteria and algae from growing in your pool. Bromine is another popular disinfectant, and is commonly used in spas because it lacks the strong chemical odor of chlorine. You can use either chemical to keep your pool clean. Whichever you choose, it is important to keep level of chemicals at a safe but effective level. If necessary, you can add chlorine or bromine to the water using dissolving tablets.

Adding Chlorine

Step 1

Use your chlorine test kit to measure the chlorine level of the pool. Fill the tester with water from at least 30 cm below the surface of the water and at least 30 cm from the wall of the pool. Add a test tablet to the sample, and let it dissolve. The water sample will turn a color, indicating the free chlorine level in the pool.

Step 2

Compare the color of the water sample with the chart that came with your test kit. You want the free chlorine content of your pool to be between one and three parts per million ("ppm.") Only add chlorine if the test shows that the chlorine level is below one ppm.

Step 3

Add chlorine by placing a chlorine tablet in a floating chlorinator, and then putting the chlorinator in the pool. The chlorinator will float on the surface of the pool, allowing the chlorine tablet to slowly dissolve.

Step 4

"Shock" the pool with a heavy dose of chlorine about every two weeks, or if algae starts to grow or the water turns green. When you shock the pool, add enough chlorine so that the free chlorine level is between six and ten ppm. You can buy concentrated chlorine meant for shocking the pool from any pool supply store.

Adding Bromine

Step 1

Measure the bromine level in your pool using a bromine test kit. Various kinds of test kits are available, including test strips and kits that change the color of a water sample. Follow the instructions that came with your test kit.You should test the bromine level every few days, or every day if the weather has been hot or rainy.

Step 2

Add bromine to the pool if the test indicates that the level is below two ppm. The ideal bromine level is between two and four ppm. Add a bromine tablet to a floater, which will keep the tablet on the surface of the water while it dissolves. You'll need to babysit the floater to keep it out of the skimmer, as the suction will pull the floater in. Do not add the bromine tablet to the skimmer basket.

Step 3

Shock the pool every two weeks, or weekly in hot, sunny weather. Bromine is a good disinfectant but a bad oxidizer, so you need to shock the pool to kill any algae and remove ammonia, which interferes with the bromine.


Douglas Quaid

Based in Los Angeles but born and bred in Brooklyn, N.Y., Douglas Quaid has been writing for various websites since 2010. He holds a Bachelor of Arts in film from Bard College.