Humidifier with good performance and capacity

The humidifier works quietly and effectively, has a large tank of 4.5 liters, which is about consuming a pint a night at the smallest setting evaporation and therefore runs much longer than the specified 15 hours that apply to the maximum setting.
Operation is simple, the manual extent understandable that function properly.
However, since now the growing season begins, the humidity rises already rapidly, so that a further use of the device raises the moisture content of the air may be too strong. (Optimal is a relative humidity between 40 and 60%.)
Since then is also a lack of the device: Without hygrometer it's actually useless. Whoever has none, the purchase of such must necessarily plan.
Another shortcoming I find the pointed shape of the device, which makes it difficult to fill water into the tank, because the shell does not turn upside down, you have it with one hand hold, while all pouring with the other water.

But the Medisana Humidifier appealed to me especially because in the description of a water filter is specifically touted. Meant, however, is only the usual capsule with ceramic balls, which also serves as a closure of the water tank.
Any measures of upstream water filter I would have found innovative, because an experience with an ordered years ago Luftbefeuchtungsgerät of the same design was that it is recommended especially in hard water, use only distilled water. The unit had spit namely despite filling of filtered water (Brita) white lime dust around and so all furniture etc. covered, which is why I sent back the power back then.
Because of Medisana is otherwise constructed, you can run out of problems if you want to use very hard water.
Irritating is the specification in the manual, they could or should change the water filter every four weeks. I have looked on the side of company Medisana and also generally on the Internet. I could not find any available water filter of this type. This filter is actually identical to that of a slightly more compact Luftbefeuchtungsgerät branded Mesko, which I think no worse compared as the Medisanagerät (only cheaper).

I therefore give the recommendation further, as I have read in a care instructions for such water mister: Use distilled water, put about every four weeks the water filter for fifteen minutes in a glass with vinegar, rinse well and otherwise the instructions for cleaning and care of the follow instrument.

Then the unit with its large tank is quite usable.