GoKawiilReverse osmosis systems explained: costs, tank vs tankless, and what they filter out
A review of under-sink reverse osmosis (RO) water filtration explains that RO removes far more contaminants than basic carbon filters, including lead, nitrate, arsenic and PFAS 'forever chemicals.' It notes two system types: tanked RO units that filter passively without electricity, and pricier tankless units that filter on demand but require power. Industrial water treatment expert John Voll says US tap water is generally safe, but contamination problems are local rather than nationwide.