To improve water quality with the best RO membrane water purifiers, choose a high-quality RO membrane designed for efficient filtration. A good membrane effectively removes contaminants, including dissolved salts, bacteria, and heavy metals, ensuring clean and safe drinking water. Consider membranes with a high rejection rate, such as those rated for 75% or higher, to maximize water purity. Regular maintenance, including timely replacement of the RO membrane and other components like pre-filters, ensures optimal performance. Additionally, select a purifier with multiple stages, such as UV and UF filters, for enhanced protection against various impurities in water.