Well, something very strange has happened this past week. While I was out of town, my favorite angelfish got himself wedged behind my heater and died. Two days later I found my other angelfish (I had only two) dead when I got off work. He was perfectly fine that morning, chipper as ever, ate out of my hand as usual, didn't seem upset that his buddy died (hehe, if fish get upset). He had no markings or cuts on his body and perfect fins. His color had just faded. I immediately tested all my water parameters and everything was fine. I did a 25% water change, counted my losses, and called it a day. The next day, six of my rummy-nose tetras and one of my harlequin rasboras were floating belly up. What the heck is going on?? My discus are happy as larks but who's to say they won't be dead when I get home today? My water is fine, and my fish seem fine...they're just slowly dying off. Any comment is welcome.