Where should the water from a co2 reactor be introduced into the tank?

[red devil]

I am going to put a volcano in a heavily planted tank. The volcano will have as aggressive an aerator I can find to help it look like it is erupting. I know that agitating water helps dispel co2. I was wondering if I had the co2 water pumped under the substrate of the plants ( a bit like a rugf) and released there if it would give the co2 in the water more opportunity to be absorbed by the plants?

[geofied]

The lower you inject the CO2, the more time it has to contact and diffuse in the water on it's way up to the surface. However you will want to do as much diffusion as possible while it is in the water to minimize the inevitable release the air bubbler is going to promote at the surface.

[Lansirill]

I tried burying my CO2 tube in the gravel and all that it did was ensure that the tube was partially covered by gravel. When I aimed my stream of bubbles (accidentally) so that they would collect underneath a partially submerged brace of my tank, however, the CO2 levels in my tank jumped very nicely. If you can float something at the top of the tank for the bubbles to collect in, or (I've read) use the plastic 'ladder' in the Hagen CO2 system, it's ++good.

[Espada]

It doesn't mater if your reactor dissolves all CO2.

[Slappy*McFish]

Many people inject CO2 through the venturi of a powerhead placed well below the surface. I'd recommend using the reactor to feed the powerhead's venturi. The powerhead will then circulate the CO2 enriched water throughout the tank.