Does anyone have words of wisdom for what should be done to make sure water in the manufacturer issue water tank is good at the beginning of the season?

I have been putting in a half cup of Chlorox into a full water tank and letting it sit for a couple days. Too much Chlorox? Too little? Too long? It is difficult to boil the water while in the water tank, I have found. Suggestions? Secrets? Will I die this year a few minutes after my first Bourbon and water?