I dutifully changed half the water twice a week. I had heard that goldfish are hearty; yet, I've already killed Sonny.There was a bit of slime on the edge of the tank. I did my research on the Internet. I knew that a little algae is healthy as it balances pH. I also knew that the best way to deal with it is with the edge of a credit card. In my wisdom though I half emptied the tank and scrubbed with a new kitchen sponge. Within hours Sonny was dead. By the time I realized there must have been some chemicals in the sponge Cher was also sick. She lay near the bottom of the tank breathing heavily.
I changed half the water again. By morning she was the same, so I did the same. As the tank is at my computer in the living room, I've had to endure the agony of watching hers. By afternoon, I pulled apart the whole tank, washed everything, and put Cher back in. She's still not better.
At the time of this writing I'm not sure whether I'll have two deaths on my hands and conscience. Goldfish can last five years but through my negligence, Sonny and Cher may end up having lived here only a month!