Placement fo DIY CO2 diffuser?

Question

I made one of those 2 liter bottle CO2 diffuser things...I know they aren't supposed to work that great but...eh. Where s the best place to put it? Do I shove it in the filter so the bubbles come down with the water flow, or just throw it in the tank? Just so the bubbles don't immediately surface and pop.\

Thanks for reading.

Answer 1

Put it in the filter intake. It will make the PH drop violently. Mine went from 7.8 to about 6 something. I hope you read up and don't have any fish in the tank. Otherwise buy a ph increaser. and test it in a separate tank.

Answer 2

If your filter is an HOB, injecting the CO2 straight into its input would negate the entire process.  As the water comes into contact with the air, the excess CO2 in the water will diffuse right into the air, meaning virtually none of the CO2 will reach the plants.  It is a good idea to minimize surface agitation when injecting CO2 for this very reason.  With a canister filter, this works very well, but anything that is open air will be useless.  I would recommend draping a piece of cloth, pantyhose, or filter floss over the filter output to minimize agitation, and then put the diffuser in the far corner, away from the filter.