What causes this?
47g bow front.
5 fancy goldfish. 4 are 3-5in. One is 2in. I know it's overcrowded. I'm going to remove the large one soon, then there will be 4 dragon eyes.
1 dojo loach. 5in. Is the loach a threat? I like him cause he cleans well.
1 clown Pleco which is 4 years old and...