Simply drinking more water - but changing neither diet or exercise - will not cause weight loss.
However unless the body is well hydrated, weight loss will be far from optimal. Also, research shows that we do tend to eat less when we drink water rather than a sugar-sweetened beverage (i.e. we don't reduce our food intake when having high calorie drinks).
There are many opinions on this with many people touting absolute amounts such as 8 glasses a day. This is not particularly helpful as we come in all shapes and sizes, different kind of climates, and different exercise schedules.
However, many of us don't drink enough water, and could benefit from increasing water intake.
Take your body weight in pounds, divide by two. This gives you a rough estimate in ounces of how much to drink. If you weigh 140 pounds you can aim for 70 ounces (or 8.75 glasses) per day.
Water should be consumed evenly throughout the day. If you gulp down a gallon of water at once - most of it will pass straight to your bladder.
Always keep well hydrated!
Whoever had the brain child to market bottled water was a genius. In western society with the cleanest water supply in the world, people still feel the need to drink water from a bottle and not the tap.
Most studies have shown that bottled water usually is tap water filtered to get rid of the chlorine. Save a lot of money and just get a simple water filter for your tap that gets rid of the chlorine and you'll be fine, besides the plastic can actually leach into the bottled water and give it a funny taste or cause health concerns especially if the bottle is exposed to sunlight.
Another gimmick is the oxygenated water fad that's being promoted around the internet. There is no scientific evidence that super oxygenating water has any health benefits and the oxygen will just be released as you drink it and will not make it to your blood stream.
Water is 2 atoms of Hydrogen and 1 atom of Oxygen and no device will change that. If the device did you wouldn't want to drink it because it wouldn't be water anymore. In fact, Hydrogen peroxide is 2 atoms of oxygen linked with two atoms of Hydrogen and if you drank eight glasses of that, you'd be in trouble..