Hello Jean,
Thank you for your feedback and for your constructive comments. We understand that the cover, while playing an essential protective role against light, can limit visibility of the level of filtered water. We recommend lifting the cover slightly if you want to check how much water is left.
Regarding overflow, it is important not to fill the upper tank when the lower tank is full. As there is no seal between the two tanks, this can lead to overflow from the central part. We recommend filling the upper tank in thirds, as this is the simplest and safest way to avoid this type of inconvenience.
Thank you again for your trust and understanding. We remain at your disposal for any other questions or needs.
Good day,
The Monderma team
