I am not a big fan of the continued use of oxidation therapy. When you need it, use it. When your issue resolves, move on to antioxidant therapy and a good diet.
A liter a day is good.
If you add twice as much water, you cut the concentration in half. This cuts the potency in half as well.
"Stabilized oxygen" was the name given to sodium chlorite some 60+ years ago. At that time, people thought that it would add oxygen to the body. If you take sodium chlorite your blood levels of oxygen will increase over the short term, but it is not from the sodium chlorite. The sodium chlorite oxidizes weak and dying blood cells stimulating the body to product new cells. These new cells are more efficient at bring oxygen into the blood and the body. In order to keep the ingredients secret, the marketing people coined the name "stabilized oxygen."