There seems to be many types of chlorine on the market, and you will find a very wide range of prices. Each pool supply company works hard to make their chlorine product seem new and different, but upon close inspection you will find that the only real difference that may separate one brand of chlorine from another is the concentration of the active ingredients in the chemical. When comparing brands of chlorine you should expect a concentration of 99.5% Sodium Dichloro-S-Triazinetrione in granular chlorine, and a concentration of 99% Trichloro-S-Triazinetrione in chlorine tablets or sticks.

The most common chlorine is available in 3” tablets, 1” tablets, sticks and in a granular form. The type of chlorine you should use depends upon your application and your preferences or pool maintenance habits. The most common (and therefore the least expensive) form of chlorine is 3” tablets. 3” tablets are slow dissolving, which means they require less maintenance. A floating chlorine feeder or automatic feeder can be filled with a large quantity of 3” tablets, and maintain the proper chlorine level in your pool water for a week or more without any work from the pool owner.

Chlorine sticks are larger and dissolve even slower than 3 inch chlorine tablets. 1 inch chlorine tablets are smaller and dissolve more quickly than 3” chlorine tablets. 1” chlorine tablets are better suited to smaller swimming pools and spas.

The final common form of chlorine is Granular chlorine. Granular chlorine must be pre-dissolved in a bucket of water, and added to a swimming pool on an almost daily basis. This allows very precise control over the chlorine level of the swimming pool, but requires daily testing and addition of the chemical.