I bought 2 Humidity Killer because our bedroom is einerm multi-family house in the basement and we are constantly a humidity of 70% - 85% had. The moisture Killer have each about 500 ml a day - 700 ml moisture pulled from the air for as long until the stones almost 'disappeared' were.
In the meantime, has found out that the wall of our bedroom window is not properly insulated and moisture coming from the ground. This has been fixed and we now have peace.
I for one am very happy with the room dehumidifiers and would not hesitate to buy a refill.