All Pool Chlorine is not the same.

There are many styles of chlorine used in swimming pools, although they all belong to the same class of product, they do their jobs differently.

1. Pool Liquid Chlorine and Laundry Bleach are different. Pool liquid chlorine (10-12.5%) is fresher and stronger than laundry bleach (3-4%). This difference may not seem like much, but pool liquid chlorine is approximately 4x stronger than laundry bleach, thus requiring much more laundry bleach to do the same thing.
2. Different chlorines have different strengths and a wide variance of pH levels. Liquid Chlorine has a pH close to 13 while chlorine tablets have a pH close to 3. Other “shocks” vary throughout that range. This means a lot due to pH levels having an affect on the effectiveness of the chlorine within your pool water.
3. Shock bags and chlorine tablets do different things. Chlorine tablets are used to create a low level of constant chlorine in the water (sanitization) while bags of shock or liquid chlorine are meant to create a temporary high level of chlorine in a pool (oxidization).
4. All chlorine can be ‘stabilized’. Stabilizer/Conditioner are nomenclature for cyanuric acid (abbreviated CYA). CYA can get too high (>80ppm) in pool water which decreases chlorine effectiveness, the higher the CYA level the less effective chlorine becomes. Chlorine tablets have CYA built into them which helps with low level chlorine sanitization. Sodium dichlor, sometimes used as a ‘shock’ product also has cyanuric acid built in. Too much use of either of these products may cause an increased CYA level. Calcium Hypochlorite, Lithium Hypochlorite, and Sodium Hypochlorite (liquid chlorine) have no CYA in them at all, thus allowing them to create a temporary high chlorine (>10ppm) for traditional oxidizing without leaving behind any cyanuric acid.
5.  Liquid Chlorine (sodium hypochlorite) is generated in a salt pool, this is part of the reason why pH levels in salt pools tend to fluctuate on the high side and why salt pool chlorine generator manufacturers tend to suggest having a cyanuric acid level of 70-80ppm.