This is a prototype of an aquarium CO2 diffuser for planted tanks. Alternatively, it could be used as an interesting interactive air nozzle.  

This was created as an entry to the aquarium competition and was mocked up in Fusion and was plotted with 0.20 layers in PETG with organic supports. The v1 test print took about 30hrs and 40mins to print. 

It was intended to use a 6mm airline for Air or CO2 delivery. 

As a test water was poured onto the part to establish if the inverted coil would work and it seemed to work fine. Once installed in the tank it should allow air to flow upwards. 

Ultimate design will

• have opportunity to add weights to model,
• allow possible stacking functionality,
• maximize the number of loops. The diffuser distance is about 1.2 meters long. The CO2 based on the other diffusers I have seen should be completely absorbed by time it reaches the top. I am looking at reducing the number up loops in the helix to allow fish to swim through and possibly interact with the bubbles more.
• possibly add a fixed solid base to allow a stone or sand to be placed. This maybe an optional part, 
• look to add little slots to allow use of cable ties to anchor to egg crate too.
• reduced buoyancy (to avoid use of weights).

Work in progress…

MK2 update. I've changed the design to make. 

• The diameter larger - for ease of putting hands in the helix to cleanup support and future cleaning,
• The bubble channel has a larger width,
• I have made the spacing between the helix larger for fish navigation, this means the helix is about 1.41m long now,
• I have made a base part - this will need to be glued for now. I will add hole for cable ties or filament dowel (heated at end to create a molten ball to flatten)
• I have added a small hole at apex of channel to allow bubble if any to escape

I will further iterate this design and when I am happy with release with a part that can be modified. the license at moment is locked down as it a prototype. 

Plot as solid so that the weight overcomes the buoyancy. if you have less dense infill it will act as a float. ( i haven't done any buoyancy calcs or tests at this time. I plot everything with 4 perimeters for strength. which was used in the v1 and subsequent iterations will be the same. 

This has not been printed as it is a long print and I would like to do some further iteration before committing more filament. 

With regards to adding weights mentioned in v1 - I may add a version with hollow uprights so that the print can be paused, and fish weights added. This version would require more perimeters to reduce or negate leaching of lead or iron into the tank. it is suggested to spray weights with food safe epoxy or clearcoat would be best.