Breeder Box / HOB Filter / Incubator

Hey everyone,

I’ve been experimenting with different ways to collect fish eggs, and one of the most reliable methods I’ve found is the automatic egg collection system—something usually only possible with a breeder box. 

The issue is that commercially available boxes in the U.S. cost around $25 each, which makes it hard to set up multiple tanks without spending a lot.

So, I decided to design my own 3D-printable breeder box that’s affordable, multi-purpose, and easy to run with just an air pump. It works by creating a gentle air-driven flow that continuously pulls water into the box and allows it to overflow safely back into the tank—keeping water moving, oxygenated, and ideal for hatching eggs or raising fry. 

This design can also function as a small hang-on-back (HOB) filter or an incubator depending on how you set it up. I’m planning to release different modular attachments to expand its use even further.

I’m not a professional designer—this took a lot of trial and error and quite a bit of time to get right. If this project saves you money or helps you out, I’d really appreciate a boost. It costs you nothing, but it really means a lot and helps me keep making more useful designs for the community.

Thanks and happy printing!