how much bleach would u suggest for a 85 gal holding tank to purify it prior to filling with water?  I have been told a cup, a quart, gallon?  Thanks for your help

A new. 2014 bounder 36E owner.....

ToniB

the factory manual says 1/2 cup per 15 gallons , you don't have to totally fill it , just enough to fill all the lines and hot water tank and then let it sit for 3-4 hours then drain and flush