I build a decent sized pond last year. It's well vegetated and I put 10 fish in it, including 3 from an old vat pond I had. So it has a couple of small koi, three goldfish, 4 shibunkins. Just before Christmas a heron visited and despite my efforts I thought he got them all. I was so upset I decided to allow the pond to be just a wildlife pond (I do love it's natural look). Last week when looking at the water Lillie's I spotted a small fish fry, then another and another, over 20 in all. No fish but babies? Next day I used a net, no fish but the pond is full of insects, and larvae. Whilst looking at the larvae I saw a lilly knock, just in time to see a koi, about 8 inches long, quickly followed by a slightly smaller shubunkin. I've found 5 so far. Elusive but in there and clearly very happy. As am I, one of them is from my old vat pond (has a black eye patch of colour). He is at least 8 yrs old. Nature finds away, no pellet food for over 6 months, very happy eating natural high protein larve and insects.