Manual Growing lights

Natupol Excel (see figure 1.3 & 1.4). This hive is equipped with a blue hive door (in the visible spectrum for bumblebees) and has a special, flower shaped [...] bumblebees find their way back to their own hive. Tests showed that the blue door led to 12% more direct entries of bumblebees into the hive. Figure 1.3 UV