bitten

Request Help Tank size: 20Liter pH: N/A ammonia: N/A nitrite:N/A nitrate:N/A kH:N/A gH:N/A tank temp: 25c Fish Symptoms (include full description including lesion, color, location, fish behavior): I have two Koi fish that my girlfriend gift me about a year ago, two days ago i notice that one...

Hello. I have a ten gallon tank with four male guppies, two female guppies, one pleco, one black ghost knife, two goldfish and two angelfish. I know it's very overcrowded and the species are mixed but I like it that way. Don't tell me that I'm a irresponsible fish keeper or what. Today when I...