Aquarium Shrimp Trap

If your aquarium is overrun with Neocardina shrimp, here's a trap designed to catch them safely. Load it with an algae wafer, twist on the friction-fit lid and drop it in the fish tank. As printed in PETG with 20% infill, it sinks — no weights required. Leave it overnight, then retrieve it and examine your catch. My first try captured about 20 shrimp. Will probably work on other small aquatic critters. Trap size is 2.25" diameter, 3.875" tall.

Print instructions

Use a brim when printing so the models don't shift on the bed. No supports necessary.