Comets (AKA Feeder Goldfish) and Shubunkin are tough fish.
We lost all our Koi last winter to a freak temperature drop.
Temps had been in the 60's then dropped to the low 20's.
If the Koi are taken down in temps slowly. They overwinter fine in water just above freezing.
Water temps dropped by 30° almost overnight. Koi all were still way to active and perished.
The Comets and Shubunkin were all fine.... even 1 inch long Shubunkin babies.
