The industry has approved a 40-inch duration as a standard size to ensure that membranes from diverse manufacturers are interchangeable in machines systems. Certainly one of the main measurements of a membrane is its sq. footage. Membranes are available in the selection of 350-450 square ft of surface area space. https://collinpsrco.answerblogs.com/7326938/a-review-of-ro-membrane-pore-size