Here are some photos of my fish. It seems there are two of them that look like cardinal tetras.
Cause they are cardinal tetras

Here are some photos of my fish. It seems there are two of them that look like cardinal tetras.
I am MUCH encouraged to think that I have finally found the cause of my water quality problems. As soon as I got home tonight I did a 40% water change and sucked up as much of the rotting food out of the tank as I could. I would like to skip feeding them today. I hope that is okay. What do you all say to skipping a day of food now and then? In about an hour I will do testing to see what I get.There's your problem.... you have been overfeeding 90%. Don't believe everything you hear or read. Plenty of shops and books still tell you you can keep goldfish (plural) in a bowl or 10 G tank. The "stomach" of a small fish is about the size of it's eye.
Just ask on the forum... there are many here who have been doing it for decades.