You can use the Hagen ladder to diffuse the CO2 and eliminate the need for a bubble counter in your 30 gallon cube. If this is for a different, larger, tank, you might want to go with the inline reactor, which will require a bubble counter. If you switch to the inline reactor and use a bubble counter, you can mix glycerin and water to make a bubble counter fluid. I found glycerin in the baking section of the local grocery store intended as an ingredient for frosting. Water works fine though, you just have to keep an eye on it as it will evaporate slowly.
Aquascape? I'm a crypt farmer.
It's a fine line between fishing and standing on the shore looking like an idiot.
That IS an aquascape, it's titled "The Vacant Lot".