I have a planted fish tank with some White Cloud Minnows, Celestial Pearl Danios, and Ramshorn Snails. I came back from a wedding out of town the other day and found that I had a few Danio fry in the tank. Not wanting them to get sucked into the filtration, I made them a refuge that I could 3D print and hang on the tank edge. It gets fresh water from an air uplift system, and drains from a hole in the side. Credit for Lowell’s Fish Lab for the inspiration (I paid for his design on his patreon, despite not using it, just because I blatantly used a number of his design features). I wanted one that was smaller and printed faster, so this is what I came up with.