 Chlorines, chloramines, hydrolysable phosphates, volatile organic compounds(VOC's) and pesticides, all found in tap water, will all pass through a reverse osmosis membrane unless they are pre-filtered, which could result to diseases like typhoid.  Reverse osmosis has low P H, making the water more acidic. The acidic water may also causes leaching of some metal from pipes.  Reverse osmosis waste a large portion of the water that runs through the system.  Reverse osmosis system are very slow to produce water, system generally produce only 1 to 2 gallon of water per hour.  R/O membrane will not only remove the hardness from your tap water it is also capable of empting electrons off water molecules making the filtered water acidic, (pH less than 7). Making the water unhealthy for drinking.

 Softening (removal of hardness)does not reduce water salinity but it merely remove the hardness ions and replaces them with sodium.  De- alkalization (removal of bicarbonate)it reduce the salinity of water,by removing hardness cations and bicarbonate anion.  Decationisation (removal of all cations)it is used to removal the carbon dioxide formed in water.

 Demineralisation (removal of all ions)in this application all ion in water are been removed.

 These days, it is remarkable that revers osmosis is progressively being used even in industrial application.  Currently the procedure is generally used to treat industrial waste water.  In the pharmaceutical industry, reverse osmosis is used to method mark water which in turn is used for different pharmaceutical requests.  In a food or beverage plant, reverse osmosis is often used to treat plant services water and boiler water.

 In many countries, many businesses are well know to produce and sell purified and safe portable water for drinking and cooking.  In the middle east and north Africa, reverse osmosis has bee try and its was successful.  It is harder to imagine a country that is not using reverse osmosis system to treat water. in the coming future,it is predictable that the use and advantage of reverse osmosis would further expand to get more industries and segment involves.

 Researchers should develop a wide number of solutions to water hardness because it has effect on human health.  governments should help to reduce impediments to testing and verification, with formative and summative analysis of efficacy of nanotechnologys.  We should develop new business model to finance water purification solution and enable appropriate technologies to be put into practice.  We should involves in discovering and creating new materials to water treatment.  We need to make new appropriate water treatment system.

Azoulay, A. Garzon, P. & Eisenberg, M.J. 2001: Comparison of the Mineral Content of Tap Water and Bottled Waters. J Gen Intern Med. 16(3): 168– 175. Eisenberg MJ. 1992: Magnesium deficiency and sudden death. Am Heart J. 124(2): Marx A, Neutra, R.R. 1999: Magnesium in drinking water and ischemic heart disease. Epidemiol Rev.19:258–72.