With CO2 injection you will probably use a reactor inline, or a diffuser of some sort in the tank. The diffuser option will put CO2 bubbles in the tank. It will be less efficient at dissolving the CO2 and of course the bubbles will be visible.
This is a decent compilation of the methods available to you:
http://www.plantedtank.net/forums/showthread.php?t=423713
If I was dealing with a tank as large as yours I would definitely consider a canister filter with a reactor inline. If you already have your filtration covered then you could consider an additional smaller canister filter just for the purpose of dissolving CO2.
This is a decent compilation of the methods available to you:
http://www.plantedtank.net/forums/showthread.php?t=423713
If I was dealing with a tank as large as yours I would definitely consider a canister filter with a reactor inline. If you already have your filtration covered then you could consider an additional smaller canister filter just for the purpose of dissolving CO2.