Hi, Eric, if you have CF, the 30 mg/pound/day (or 66 mg//kg//day) is probably a minimum for what you should take. Some doctors, such as Dr. Visca, use even higher doses. For one capsule of the inhaled, 3ml or less of water would be about the right amount. Much over 4 ml, and you will get a hypotonic solution that will be irritating.