Chloride attacks Stainless Steel
Chlorine is a great way to make your water safe, but if you have a stainless steel tank, it can cause serious long term metallurgical damage that is not initially apparent. Chloride attack can damage the stainless, particularly at welds, and can be destructive of other metal components in your faucets and pump housings.
Chlorides will attack the stainless and make it quite brittle over time, permitting hairline cracks to develop near welds and stress areas followed by mysterious leaks that are difficult to locate. This can be very problematic in the hot water system.
I would suggest that you careful to flush out the system with clean water after the chlorine "shock" treatment. It generaly takes a while for the damage to occur, but having highly chlorinated water sit without motion will cause damage faster.
Polyethylene tanks are likely ok with chlorides, but all the metal components exposed in the system can be affected.