@mngrif Ive done a lot of pure hydro but there will be some unique difficulties with fish. To increase root O2 for plants just add a little hydrogen peroxide. But actually degassing the CO2 in the water itself, i dunno. I was under the impression an air pump will usually inject O2 and since this competes with CO2 in terms of dissolving it, it should cause the co2 to more readily leave the water.

Similar to how in the lungs similar mechanisms work.

Rgardless if it just comes down to surface area I would think that could be solved easily enough with some creativity. A waterfall or neblulizer of some kind running constantly would effectively increase surface area.