I use bottom tray when I want to collect some pollen and during the winter. Bottom board is always perfectly clean. Actually bees polished plastic to a gloss. It easier to keep clean as bees do not need to drag rubbish to the entrance. Just sweep it to the closest hole in the grating and job is done.
However, bees do not have an access to the bottom tray when it is installed. Rubbish accumulates there. In the winter I pull it out every couple weeks to see what is happening there, give it a quick wash and put it back.
1 Like