This is a multi-sectional house for fish about 180 mm high. Holes not less than 14 mm. Suitable for guppies or danios.
Use a safe plastic like PLA and make sure that there are no sharp edges, which fish can damage fins.
I do not recommend using supports because it's very hard to delete them. Your printer should be able to print overhangs about 60 degrees.
I used PLA, line 1.0 and layer 0.2.
Later, a version with less overhangs will be added.