My auntie and uncle have a pond set up in their garden, approx 250G, it runs a 1500G pond filter, unsure of the make but I have seen it.

Their pond has been stocked and running fine since approximately march time this year.

Speaking to my aunt today she mentioned that was her about to stop feeding the fish for the winter. Now to me I would think they need food over the winter.
But I don't have a pond so thought the AC could give me an answer

Approximate stocking is;
2-4 common goldfish, no bigger than 6 inches each.
1 or 2 koi, no bigger than 6 inches each.

Cheers guys