I have a 10 gallon tank that I am going to turn into a dwarf puffer tank. It will be planted, with DIY CO2, and has 3 wpg of lighting. I have driftwood and rocks already. I was thinking about using Eco-complete as the substrate. I was wondering what types of plants I should stock and if eco-complete was a good substrate to use? Also, whats the best way to diffuse the CO2. I am going to use an empty soda bottle for the CO2. I know you shouldn't use CO2 when the lights are off, so should I get a valve of some sort to control the flow, or just remove the tubing when the lights go off? Any suggestions would be greatly appreciated. Thanks