You can download a program called BleachCalc and it will tell you how much bleach to add, among alot of other great things. It comes configured for metric measurements, but you can change the settings in the top somewhere. You can also see at the top that you can calculate the gallons of your pool, which you will need to enter in to get the correct bleach content.

Once your bleach stays overnight, you should take the DE filter apart and clean it, and put new DE in it.

Here is a nice summary: click me!