I would say that if at all you want to use reverse osmosis bring enough catridges and base unit from US. It is definetly costly here. Further,I myself being and environmental engineer have never used RO and neither bottled water. what i do is boil the water and filter through batch type ceramic filter candle. The best but cumbersome. Mine is a small family. Principally it depends on raw water quality, qatar has good qaulity.