Drink water to control your blood pressure

At the last 3 monthes a have a high blood pressure for some reasning of life pressuers and the full mind thinking, as a way to control this blood pressure a doctor have told me a way to do that without taking any medicin I was not believing in that at the first but when I continur use this way my pressure was good and my body was good too.
The way is as he told me to drink 1 liter of water on the early morning or when you get up from your sleep but it is good to drink it in the early morning at 5am then if you can sleep again go to sleep and if you cant you must eat after you drink the water at least 1 hour, what happen realy is the water making a filtaring to your body and your kidneies and make the blood more smooth to turn on its cercil in our body.
Try to use this way and tell me what happen to you, it will be hard at the first time to drink this mount of water at the early morning but you will be use for it.