There is a common misconception from a lot of pool owners that household bleach and chlorine are the same product and can be used interchangeably. Shocking your pool weekly is an important factor in maintaining a clear and safe pool, but you should make sure you are using the correct products!
Bleach and chlorine are similar in that they both have disinfecting materials in their formula. Bleach has about a 5% chlorine content, while the remaining percentage is water and salt. Household bleaches could also contain additives such as fragrance, which is bad for your pool system. While bleach is cheaper upfront, there is a good chance it will lead to constant chemical management or cause your pool to be out of balance or not safe.
Chlorine is one of the most important chemicals you can use in your pool. Chlorine is in the form of Calcium hypochlorite. It is specifically made for water disinfection purposes, especially swimming pools. The fact that is is formulated for pools is a huge advantage to using pool chlorine. Chlorine also contains calcium hypochlorite chlorine at around 65% strength. This is a huge difference from the 5% bleach contains. Pool chlorine is stronger and designed to stay in your water for as long as possible, amplifying the sanitizing power of the shock.
Bottom Line: What Should You Use?
Chlorine is the winner if you are looking for effectivity and best results. It has a high content of the calcium water needs to destroy bacteria. It is also formulated specifically for pool water and will provide the best outcome. Bleach is weaker, meaning you would have to add more in order to get the same results. It can also cause other problems for your pool water and system. Household bleach may work in a pinch but it should not be used as the primary means of keeping your pool safe and in balance.