Reverse osmosis rejects bacteria, salts, sugars, proteins and other elements that have a molecular weight of greater than 150-250 daltons. So, if someone tells you that you can have better health through reverse osmosis system, he or she is talking for the sake of talking or for promoting his or her reverse osmosis system. To minimize this build-up, a flush cycle needs to be applied. Reverse osmosis costs 18 to 24 cents per gallon. They are also notorious for being slow because they produce less than a gallon of water per hour. Using a reverse osmosis system may be cheaper than drinking bottled water but it is by no means inexpensive. Using a reverse osmosis system may be cheaper than drinking bottled water but it is by no means inexpensive. It takes approximately 3 to 4 hours to clean a gallon of water. Why not just use a carbon filter in the first place. Reverse osmosis rejects bacteria, salts, sugars, proteins and other elements that have a molecular weight of greater than 150-250 daltons. So, if someone tells you that you can have better health through reverse osmosis system, he or she is talking for the sake of talking or for promoting his or her reverse osmosis system. To minimize this build-up, a flush cycle needs to be applied. Reverse osmosis costs 18 to 24 cents per gallon. They are also notorious for being slow because they produce less than a gallon of water per hour. Using a reverse osmosis system may be cheaper than drinking bottled water but it is by no means inexpensive.