What's With Chlorine
First, How Does Chlorine Clean Your Pool Water
When you add Chlorine to your pool water, it attaches to bacteria and other organics on the molecular level to kill those unwanted contaminants. When that chlorine “combines” with the bacteria and organics in the water, those chlorine molecules become inactive and no longer work to sanitize your water.
This combined chlorine and contaminants are then burned up by your weekly super chlorination (shock) treatment. The chlorine level of a swimming pool should be kept at 1-3 ppm at all times to ensure that the pool water is clean and safe for swimming. If you have a mineral system installed, then you typically keep the level at .05
Which Type of Chlorine should you use?
There are many types of chlorine on the market, and when you take a closer look, you will find that the only real difference that separates one brand of chlorine from another is the concentration of the active ingredients. When comparing brands of chlorine, you should expect to find 99.% Sodium Dichlore-S-Triazinetrione in granular chlorine, and 99% Trichloro-S-Triazinetrione in chlorine tablets or sticks.
Chlorine Tablets: The most common form of chlorine are 3” tablets. The 3” Tablets are slow dissolving, so your pool requires less attention. Also available are 1-inch tablets, which dissolve more quickly than 3” tablets. 1″ tablets are better suited to smaller swimming pools. Floating chlorine or automatic feeder can be filled with several tablets and maintain a proper chlorine level in your pool water for a week or more without any work from you.
Similar to the tablets, but more expensive, are chlorine sticks. Chlorine sticks are more oversized and dissolve more slowly than 3″ chlorine tablets. This type of chlorine is suitable for both Above Ground and In-Ground Pools. I am not a fan of using this in a small kiddie pool because children may think the table or floater is a toy.
Granular Chlorine is the least used form of chlorine in swimming pools. Granular chlorine (sodium dichloride) should be pre-dissolved in a bucket of water and then added to a swimming pool daily. This allows exact control over the chlorine level of the swimming pool but requires daily testing and adding more of this chemical.
I would recommend this type of chlorine for those small kiddie pools. Granular is also a great way to establish a chlorine level in a hurry, but it can also be expensive if you want to use it regularly.
The secondary type of granular you can buy is calcium hydrochloride, which has about 65% active chlorine. The most popular use of this chlorine is weekly super chlorination (shocking). This granular type is generally less expensive and makes for a great algae killer.
Liquid Chlorine: Liquid has about 12% active chlorine. It is best used for weekly shocking and treating “problem” water. It has a meager cost and can be used for daily water treatment, much like granular chlorine. Don’t confuse Liquid chlorine with bleach, which has other additives and only contains 5-6 percent chlorine. It would work in a pinch, but you should not use it regularly.
The type of chlorine you should use depends upon your application preferences or pool maintenance habits.