While going for an RO one needs to know the water quality at his home or office. He must have an idea about pH level and see if he wants to go for an offline RO or an online one. In the case of storage also one needs to decide if he wants a unit with storage facility or not. Here one needs to note that the RO is at a little higher side in terms of cost of the device compared to the water purifier. If one feels budgetary constraints, he can also go for a local made RO, but the quality of the device cannot be assured in such a case.