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Pool Chlorine Brands - What's the Difference?

Are all pool chlorine brands the same? The short answer is no! While chlorine tablets may look the same across the board, there is usually a big difference in terms of quality and ingredients. Let's dive into what goes into making a chlorine tablet, and how to pick the best chlorine brand.

Chlorine materials


Chlorine manufacturing


Chlorine brand country of origin

Country of Origin

Chlorine Materials

Chemical labeling and MSDS sheets provide a look into the ingredients used in chlorine tablets and pool shock, but manufacturers are allowed "proprietary" license, to not list trade secret ingredients.

Trichlor tablets can contain additives to control algae or improve water clarity. In such cases, a lower percentage of available chlorine will tip you off to the use of fillers or additives. Cheaper binders can gum up chlorinators and cloud pool water. Raw materials can contain impurities or be cut with low grade fillers in cheap chlorine.

Chlorine Manufacturing

How chlorine is made does make a difference in the level of impurities, and in how the chlorine is delivered. Cheaper tableting equipment can produce a crumbly tablet that dissolves too rapidly. A chlorine product's solubility, hardness and bulk density affects the release rate and is dependent upon the heat and pressure used during tablet formation, as well as the quality and purity of ingredients.

It takes a lot of pressure and heat, and precise cooling to create a well-made chlorine tablet, and do it without harm to the environment. Less sophisticated tableting facilities produce an inferior product and discharge excessive byproducts into air and water.

Country of Origin

In recent years, chemical manufacturers in the U.S. have petitioned the International Trade Commission for protection and sanctions against imported isocyanurate products being dumped on the U.S. market. Late last year, the Dept of Commerce ruled that imported Chinese chlorine was found to be heavily subsidized by the Chinese government, and was unfair to domestic manufacturers.

Differences in Chlorine Brands

In a nutshell, there are significant differences in the quality of chlorine brands. This results in tablets that dissolve too rapidly and leave a gummy residue, and granular products that separate too slowly, and leave behind a cloudy residue.

There are many ways to make a cheap chlorine product, so stick with a major brand; and avoid private label brands and sales on "generic" pool chlorine from big box retailers, home stores or discount clubs, which are domestically packaged with imported chlorine.

No matter what type of chlorine you use — trichlor, dichlor, or cal hypo — look for a respected brand of domestic pool chlorine, and steer clear of chlorine brands of dubious origin or of poor materials and workmanship.

In The Swim makes every effort to provide accurate recommendations based upon current ANSI/APSP/ICC-5 2011 (R2022) standards, but codes and regulations change, and In The Swim assumes no liability for any omissions or errors in this article or the outcome of any project. You must always exercise reasonable caution, carefully read the label on all products, follow all product directions, follow any current codes and regulations that may apply, and consult with a licensed professional if in doubt about any procedures. In The Swim assumes no legal responsibility for your reliance or interpretation of the data contained herein, and makes no representations or warranties of any kind concerning the quality, safety, or suitability of the information, whether express or implied, including, without limitation, any implied warranties of merchantability or fitness for a particular purpose.