The unit is flexible and is inter convertible from reverse osmosis to nanofiltration membrane system, Easy to use, robust and requires very less maintenance and portable in nature, Longer membrane life and lower fouling by impurities, Greater water recovery (80%) with low rejects volume. The reject water can be reused for washing water, laundry and other purposes, Retention of sufficient mineral content, Ca, Mg, P, Na, K essential for human consumption and health, The UV lamp incorporated disinfects the permeate water making the product water safe for human consumption, The taste of the water is enhanced by post treatment using granulated activated carbon filter whereas the provision made for TDS controller in permeate line remineralize the water by providing sufficient minerals.