Thanks to everyone for taking the time to offer advice to help me with my Goldfish
. Unfortunately he died sometime today. :(
He seemed quite healthy when I bought him, and stayed that way for about three weeks. Then I noticed something wrong with his mouth. At first I suspected it was an injury but now I am wondering if he had some sort of fungus or infection in his mouth.
The water quality is very good, I check the ammonia, nitrite, and nitrate levels every water change. The last three days I did 50% water changes each day. The temperature is 23C, I check it every time I do a water change.
I will be shopping for a bigger tank and this weekend.
My other Goldfish
is still very healthy and happy. I took these pictures just a few minutes ago. Now if only I could take better pictures....