Question
How cold can the water get before it is harmfull to comets or other goldfish......
Also if a heater is used what is the lowest water temperature at which the fish
could e fed and how ofen ?

Answer
Hello Wayne!
Goldfish can survive in very cold temperatures as long as there is a hole in the ice to let oxygen in and carbon monoxide escape.
They should not, however, be fed once the water temperature drops below 48 degrees Fahrenheit. They cannot digest food at that point and feeding them could kill them.