Why Do They Die

[Marky_Mark]

i have 2 clown kuli loaches and 2 kuli loaches and i came home today to see them dead, i checked the water and all is well, i do regular water changes,and the tank is at 28 degrees, there is no fish in there to bully them so why did they die?

 

[Dubby]

Do you measure your water parameters? How long have you had the tank and the fish?