# DIY CO2 reactor for Hang On Back filter



## sar315 (Mar 31, 2013)

CO2 reactor of this design doesn't require external pumps or plumbing. 
It inserts into outflow of HOB filter and takes very little space.
Made from acrylic.

Please see attached video:


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## ElectricHead (Sep 11, 2005)

I like it! Nice idea.


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