DIY CO2 into Internal Backwall Biofilter example
I insert an airstone in the two large gravel chambers of the following diagram in one tank and it is awesome. Bubbles trickle up the gravel but are forced down by the flow giving plenty of time to dissolve, then the water is distributed throughout the tank by the multiple tiny output holes. Some may interject at the idea of an airpowered unit and CO2 together but it works really well. Consider the premise that used water going into the unit is deficient in CO2 to begin with. Nutrients can also be added to the gravel chambers for slow, even distribution.
Last edited by LAKE; 07-21-2012 at 08:56 AM.