He kiʻi kēia e hōʻike ana i ke kaʻina hana o Reverse Osmosis. Ke hoʻohana ʻia ke kaomi ʻana i ka hopena i hoʻopaʻa ʻia, koi ʻia nā molekele wai ma o ka membrane semi-permeable a ʻaʻole ʻae ʻia nā mea haumia.
Hoʻopau ka membrane osmosis hope i nā molekala i ʻoi aku ke kaumaha ma mua o ka wai, e like me ka sodium, nā pae kiʻekiʻe o ke kēpau, nā minerala i hoʻoheheʻe ʻia, a me ka fluoride. ʻO ka hope, hoʻopololei ke kānana post-carbon i ka wai.