:( Aww. They are great little fish. I love watching their little feelers/pectoral fins. Sometimes they will meet each other and almost look like they are shaking fins. I did lose one the other day though so now I only have a pair.
Good luck.....injecting CO2 is one thing I have never done and most likely never will. The natural CO2 that my systems create is plenty for the species of plants I grow.....but it does limit me on species of plants-but not much.