The filter with micro-silver (bacterial and fungal growth) is simply to rinse ... so no need to buy product. The tank has a size where you do not have to constantly refill. And the Intelligent Auto is running smoothly, and as a small plus you can still ionize the air. You can discuss the noise. Me it does not bother, the unit is running really quiet an indoor fountain or an aquarium is definitely louder. An ultrasonic atomizer can not be absolutely silent, so I think it's okay super. He easily controls 40 m2 do not have to have right in the bedroom the unit yes.