Bleaching powder usage ratios to clean water storage tanks and safety concerns

I am staying in a flat where 30,000 litre capacity water storage tank is in use. Two days ago our flat care taker added 400gm of bleaching powder to the tank. Now the drinking water after filtration has some kind of bleaching powder smell, is it safe to consume this water? Whether bleaching powder is safe for human consumption or not? If so, what is the exact ratio for this treatment?

Kindly provide suggestions in layman's terms in a easy to understand format.

Parash Phukan