That didn’t take long. I’ve just had my first fish die on me. I had noticed she was looking a little lethargic, sticking to the bottom and the sides of the tank. I decided to do a partial water change to clean up the bottom of the tank which went OK, though it stirred up a little silt. Maybe that’s what tipped her over the edge. The remaining three look to be in good health, though as I’m new to this I wouldn’t really know.