DIY co2 diffusion

[D191]

Have typically run output of yeast based system through a power head which diffuses the bubbles and can be set on a timer. This generally has worked very well. Currently have a flex 32.5 gallon tank that I don’t want a power head in. Thinking about running the output of the co2 into the sponge of the internal filter system of the flex. Assuming the sponge will contain the co2 long enough for it to disperse into water column.  Anybody out there tried diffusing co2 through a sponge inside of a filter ? 

[Seattle_Aquarist]

Hi @D191,

When I first started out with CO2 i would add the CO2 into the inlet tube of my Aquaclear HOB filter.  The bubbles would go up the intake tube, hit the impeller and explode into thousands of micro-bubbles.  Then the bubbles would get caught up in the horizontal stacked sponges in the filter chamber.  Worked just fine.  Here is one of my tanks (45 gallon tall; 24" tall) from 2009.  Hope this helps! -Roy