My first aquarium was 45 years ago, a nice community tank. Then a long dry period. A couple years ago I had a betta in a 29 gallon tank; killed anything I put in it (unlike the betta in my first tank). So, I'm about to start the 29 gallon back up. Put in a betta and a single cardinal tetra; if he doesn't kill it then I'll get some more and some pygmy cories