An underground tunnel placed in the corner of your tank where your fish can hide while you can watch them.

Burry the tunnel under your aquarium soil or gravel and let your fish explore it.

All the edges are rounded to protect you fishes' fins. With dimensions of 140mm x 140mm and a 37mm roof height, (50mm overall height, including the entrance). The entries are 30mm x 40mm. The plastic thickness is 3mm.

Materials: Pick materials that are safe for both your fish and plants. It's usually recommended to use ABS or specific food-safe PLA, and it's often advised to coat the print in a safe epoxy to seal it.