Increased water intake may increase blood pressure. In my case, cutting out sugar and white flour completely (not salt) from my diet in addition to eating healthy brought down my blood pressure to normal levels quickly. High blood pressure was something that i was struggling with for years and i wish i had known this years ago. Unfortunately i had a heart failure a couple of months ago and had 5 stents put in because of blocked arteries. I'm currently recovering and trying to get back to cycling soon. My blood presure is now in low 100's over 58-70, i do take a few medications now but BP medication is not one of them.
2 weeks before being diagnosed for heart failure (and having diabetes as well), i somehow decided on my own to cut out sugar and white flour from my diet completely and my wife and i were both surprised when my blood pressure dropped to normal levels in no time.
Also low potassium and magnesium levels may cause high blood pressure or even irregulat heart beat. Do not take high doses of potassium without consulting your doctor as it may cause problems if your kidneys aren't functioning well.