That rock isn't ADA...........
I'll have to stop by and see the rock for myself to see if I'd be interested, as well as the tank. Maybe I can move the printer under my desk and put the cube on top, light it with a few LEDs. Tax refunds are coming soon!
As for CO2, you can get 2.5lbs CO2 tanks for about $35. If this is in the same room as the 30gal, you can get a splitter. John N is selling them in the buy and sell forum. Good stuff and very easy.