The IKEA Nojig 15x20x5 cm trays fit into the IKEA Åkerbär/Akerbar greenhouse, so I made some self watering pots to go on top of the Nojig for my small plants.
I fit 4 sets into my 65 cm greenhouse.
I used the Nojig trays to be sure my water container was waterproof.
The author marked this model as their own original creation.