My hubby has the concern so we bought a water treatment thru a fren recommand. he has show us some demo and found our our tape water content chlorine. he explain to us not only chlorine got others contaminant in the water as well that why we need to sterilize baby product as baby still very small, not much immunity better keep everything as clean as possible. We don believe also at first but after my confinement lady told us then we think its necessary to have one.