Should I remove my ultraviolet light from my koi pond in the winter? If so, at about what water temperature?

Question

I live in South Carolina and have an ultraviolet light in my koi pond skimmer to keep the water clear in the summer months. Would it be wise to removed it in the winter so it will perhaps last longer? Also, should I turn off my water fall in the winter? Or at minimum not run it 24 hours a day? I have about 3 dozen goldfish and four koi. The water at the deepest part is about 30 inches.

Answer 1

I suggest that you keep everything running. The water fall is important for maintaining the oxygen level in water - you don't want your fish to die.

Answer 2

You should be fine minus the ultrviolet light. Koi and goldfish can withstand temperatures down to 35 dgrees - that is, if the pond freezes over 2 inches on top the koi and goldfish will survive under the ice okay. Koi are multi-level feeders who will eat algae as well as bugs in the water. Don't turn off the water fall as running water does not freeze as fast as stillwater. To keep them well, give them some live food periodically. Mine like to eat garden slugs and shelled garden snails as well as blackfly larvae, but they do fine without daily feedings, even in cold weather, as they and the goldfish will eat whatever insects attch themselves to the algae in the pond.
Hope they overwinter well. Is the pond protected from visiting raccoons? You might want to throw some netting over the pond in winter to protect from hungry raccoons and minks in your neighborhood looking to go fishing.