This is a prototype design for an aquarium bubbler. The safety of using 3D printed materials in aquariums with living creatures is debatable, so if you have doubts plan on using 3D printed parts in a decorative aquarium containing only plants, snails, and other robust creatures. The product is presently limited to production using the regular white strong and flexible plastic material to minimize the possible introduction of other contaminants into the tank environment.
The (144) bubbler holes in the cylindrical shell will be smaller after manufacture than they are drawn, being barely visible in the test prints I have received so far. As a result the bubbler appears to be similar to an air stone in operation. The holes may be carefully drilled out with micro-drills if desired but you'll need to be careful since it can change the behavior of the bubbler. (Too many large holes can result in just a few holes emitting bubbles, as I found after drilling out holes with a drill bit that was too large.) A tie down loop at the end of the bubbler allows it to be held in place with a hook or cord connected to a weight or other fixed objects in the tank.
If you want to try this bubbler here are other issues to think about:
1) There will likely be some nylon powder remaining inside the bubbler that needs to be removed before use. I managed to do this in a pan of water, with a tooth pick to loosen up powder inside the shell, running water from a faucet for rinsing, and a lot of shaking the bubbler with water inside for further rinsing. I received one of this style filled with powder and two others that had very little, so what you get depends on how well the good folks at Shapeways manage to remove powder before shipping.
2) Not all holes will be of uniform size so some holes locations may emit more air than others. In general the bubble pattern is a function of holes sizes, total area of all hole sizes, and air pump pressure. If you drill out holes to enlarge them the bubble pattern may change.
3) I have no idea how long a bubbler like this will last. The holes may enlarge over time or seal up from loosened nylon powder.
4) The bubbler plastic will have some roughness and surface porosity which can provide a foothold for the growth of bacteria and algae, but that's not necessarily a bad thing. If this is a problem such nylon parts can be sterilized by soaking in a diluted alcohol solution and then thoroughly rinsed in water before use.
5) The nozzle of this bubbler connects to standard 3/16" outside diameter aquarium tubing (with 1/8" inside diameter).
This is just a fun experimental design. If anyone has suggestions or would like anything customized I'd be happy to hear from you.