These koi are massive they were put in at only finger length as well, sod paying a few hundred pounds, just have patience
He's going to trade them in and get some smaller ones, partly because the food bill is huge and also because whilst the pond is very large they have got to such a size where they could use a bigger area (imo).
Very nice Will, some good fish there. Visited a mate the other day whos dad had put four little koi in a few years ago and not seen them for green water since, went fishing around and found three monster 20" fish. Amazing how well little garden centre fish do.