Karl big

Set the output to the highest level.  
For the room size to be right, not only the room height (standard 2.5 m) but also whether or not the doors to the room are closed is a determining factor. If the doors to the room are left open, the adjacent rooms will also be included in the total area. If the relative humidity is low (below 35%), the humidity will not increase immediately. That is because the floors, furniture and walls absorb the moisture first before it ends up in the air. It can take up to two weeks for everything to absorb sufficient moisture for the humidity to start rising. As long as you keep having to top up the water regularly, your Karl big is working properly. 
If the humidifier filters are more than 2 months old or the upper part is hard and no longer saturated with water, the filters should be replaced.

For the hygienic and optimal use of the humidifier, the humidifier filter should be replaced at least every two months. If you continue to use the humidifier filter for longer than this, on the one hand the humidification output may deteriorate significantly and on the other, the antibacterial action of the filter can no longer be guaranteed. You can generally purchase humidifier filters from the place where you bought your device. The filter change indicator has to be reset manually after changing the filters.

Discolouration which is slightly yellowish or brownish is normal. Discolouration is caused by the substances in the mains water or the air. The poorer the water quality, the quicker the humidifier filter will become discoloured. Although this does not look pleasant, it is harmless as long as it is not due to mould. The discolouration will not affect the performance of your humidifier either. If you have not been using the humidifier filter for very long, you can rinse it thoroughly, turn it over and reuse it. If the humidifier filter is more than 2 months old, we recommend that you replace it.

It is also possible for the top part of the humidifier filters to become hard. During the evaporation process, the lime present in the water is collected in the humidifier filter as limescale. The harder the water, the quicker the humidifier filter will become hard. If you use water from a water softener which operates based on the principle of ion exchange, salt may collect in the humidifier filter rather than limescale. If you have been using the humidifier filter for less than 2 months, you can rinse it thoroughly with water, turn it over and put it back again. It is possible that you may notice an odour after you have turned over the humidifier filter depending on how contaminated the filter is by constituents in the air or the water.

If your Karl big or the humidifier filters smell unpleasant, there may be various reasons for this: water and air quality, a worn-out filter or even the fact that you have not used your Karl big for a long time and he has still water in his tank. In any case, we recommend that you clean and descale the device thoroughly. If you have been using the filter for less than 2 months, you can rinse it thoroughly with cold, clean water, turn it over and continue to use it.  

It may be that your external hygrometer and Karl big are measuring different values because the devices have been positioned in different places (heights) in the room. Different humidity values will be measured depending on the air flow and temperature in each case. A tolerance of +/- 5 % is normal depending on the type of device. Karl big measures the humidity levels best if he is positioned in the middle of the room so that the room air can flow towards the sensor as freely as possible. If that is not possible, we recommend positioning Karl big against the wall, with a clearance of at least 30 cm. Under no circumstances should Karl big be “hidden” in a corner of the room or behind a sofa/piece of furniture because this can have a negative effect on humidity measurement as well as humidification efficiency.