Well I don't want to gas off the Co2 so I will stick with the little tetra filter.
There are many common names the puffer is sold under, dwarf, pygmy, BB, pea, malabar, indian, etc (there are more) but the one I'm talking about is Carinotetraodon travancoricus. They are easily kept in a community tank though you will often read otherwise. My main issue was making sure the more aggressive fish left them alone, not the other way around. I remember reading on another forum that they were vicious and mean and that colored my initial impression of them. I got my first one about 10 years ago and my experience with them turned out to be quite different than what I had read. They will feast on shrimp fry though. The SAP is a much different puffer.
I do like the idea of them being the main fish instead of the tetras.