Amazing portable humidifier, but it uses a lot of water. Sufficient for one day at the bare minimum. We've used up about a third of it. Regarding antibacterial, I have no opinion. This is a marvel compared to the alternative, which entails removing the tank, turning it upside down, unscrewing the filter or valve, pouring it, twisting it, turning it upside down, bringing it and setting it up, and then pouring water by opening the lid from above. And yes, as stated in the instructions, you must hoSee full review