I have been working hard on 3D frag racks that are reef safe. I have been slowly refining the technique and testing them in a quarantine tank.
Details about the frag racks:
• Printed with PLA (polyacetic acid)
• High quality biodegradable and non-toxic filament per manufacturer (seems that certain filaments do contain contaminates, especially cheap ones!)
• Body measures approximately 10cmx10cm with plug holes of 9.5mm (3/8th inch)
• Silver color
• 2 suction cups hold the item in place on the glass
3D print - Album on Imgur
I also have used ABS to print these racks. PLA and ABS are both considered reef safe. There is some concern PLA may break down over time; however, 3 months in the tank has not had any effect on the rack.
If you are interested in watching one being printed, I frequently stream using a webcam that watches the printer.
Any suggestions or requests let me know!