How may liters of water should one drink?

You need to drink 4-6 ltrs of water. It is a healthy quamtity to remove toxin from your body.

Don't drink too much water, it may make you sick.

If you want to drink much water then do it slowly.

Don't move suddenly from 2ltrs/day to 7 ltrs/day.

It gives lots of extra load/headache to your kidney.

I hope this helps you