Protein Skimmer Airstone Modular

Support Eheim 4002650 or Limewood diffusers

One of the first 3D models I ever designed was a simple airstone skimmer born out of a pressing need for my own tank. After gaining a few years of experience with Fusion360, I decided it was time to revisit that original concept and improve it. The result is this updated, multi-modular system that remains incredibly simple to operate while offering the flexibility required for different aquarium environments. I'll continue making other modules for it, but this is the start.

The core of the design is its modularity. I have included sections of various lengths so you can mix and match parts to create a custom height that fits your specific needs.

I have created a dedicated module for the Eheim Diffuser 4002650. This part is widely available and performs excellently. When installing the diffuser, make sure to apply firm pressure until you hear or feel a distinct click; this ensures a proper seal. I have also included a small plug to seal one side of the diffuser, preventing water from entering the airflow. Also, remember to adjust and test the diffuser before installing it into the skimmer.

If you are looking for the finest possible bubbles, a Limewood diffuser is the ideal choice. While they can be slightly harder to find, they are often preferred by enthusiasts for their superior bubble production. Please note that the air hose entry points on both modules are designed with very tight tolerances to prevent air (bubble) leaks. You may need a bit of patience when feeding the hose through for the first time, but the airtight seal is worth the effort.

Mounting the skimmer is straightforward thanks to a flat, square protrusion on the back of the airstone modules. This surface is designed for gluing a standard aquarium glass-cleaning magnet, allowing you to securely snap the skimmer to the side of your tank. I recommend using a reasonably strong magnet to ensure it stays in place during operation.

The collection cup and lid are designed to hold approximately 300ml of skimmate. To give you peace of mind, I added an overflow hole in the side of the cup. This acts as a safety feature, allowing excess liquid to drain back into the aquarium if the cup fills up before you have a chance to empty it. It is a practical, hobbyist-focused solution for maintaining a clean and healthy aquatic environment.

Best of luck.