Corner Aquarium Filter V1 (air-powered)

This filter is air driven, and it operates just like a sponge filter. It's compact and discreet enough to hide in a corner easily, and its various internal components allow for many possible filtration configurations. 

This is Version-1, which is designed to connect straight to the air line, no diffusers or air stones necessary. Version-2 has redesigned internals allowing for the connection of a 14mm cylindrical air stone. The air stone provides more moving surface area, and draws water through the filter more efficiently. Both versions are capable and reliable, but Version-2 has a greater flow rate.
 

Features:

-Swappable media baskets (which are also connectable using the locking tabs).

-Perforated pre-filter section (to keep larger debris out of the media).

-Inlet mesh insert (designed as a separate piece for easy replacement).

-Two filter sizes: short and tall, for different sized aquariums.
     The tall holds 3x baskets (not including the empty space at the inlet), and the short version holds 2x baskets. 

-Tube / cable pass-through. The back of the housing has two long empty channels for hiding extra air lines or cables. 

-Extra plumbing pieces for extending or bending the outlet.  This filter can be run with or without the extensions. 

-Optional air diffuser insert that can be used instead of the outlet tubes.

Assembly & Use:
Aside from the filter media and pump, the only extra piece you will need is an airline coupler for attaching to the air input on the filter housing (shown in the photos). This piece is especially small and fragile, so I prefer to use a commercially available coupler that is more durable than a printed piece would be. For the mechanical stage(s), you can put a sponge inside a basket, making it easy to grab for servicing, or you could just stuff it in with no basket. Depending on what you put inside, the filter may need to be weighted with rocks inside, otherwise it may be difficult to position. You can put the filter down on the substrate, or it can be hung by its tubing. This is made easy with the included corner bracket and tube guide for rimmed aquariums, which holds the tubing taut in the corner without restricting the air flow. *This corner piece may need to be modified to fit your aquarium's rim, I have added 2 sizes: for 25mm or 35mm rim height. The filter housing has inlet holes on all three sides, which may be useful in some cases, but most likely you will want to disable the side inlets. The Inlet mesh insert part has two variations: 1-side and 3-side. To disable the side inlets, print the 1-side version.

Printing Notes:

-The output tube pieces have been printed with fuzzy skin in my tests, and they fit well. If you prefer to print them without the fuzzy skin, then you may need to resize the ends slightly to avoid loose fittings.

-PETG and PLA are both widely accepted as aquarium safe, though PLA breaks down under water more quickly than PETG.