I've been experimenting with various injection methods from misting to in-line reactors and it seems that I get good results by just feeding CO2 into the intake of my Eheim. Is there a downside to doing it that way?

thanks,

Russ

Noise and gurgle. I think more O2 is better for the bacteria in there rather than high CO2, just like fish.
But it typically is not a large issue, I'd not worry about it.

Regards,
Tom Barr

For what it's worth, I had read that it is hard on rubber seals etc.. but after doing it in my previous setup for two+ years in my Eheim, they show no signs of deterioration.

RAS

Thanks guys. The noise is minimal with this model, an Eheim 2026. I just bought a Kent Marine venturi, so I'll be experimenting with that too.

-Russ

Why the input of the Eheim and not the output of the Eheim? Does it matter?

Bubbles hit the impeller, grinds the gas up, dissolves it.
Venturi added to the output will do the same thing but add CO2 mist directly into the tank rather than dissolving it, allowing for a direct gas into the plant as well as dissolved CO2.

Regards,
Tom Barr