For the last 4ish years I have had 3 gold fish in my turtle pond to eat mosquitos, turtles leftovers and other pest, but now they have grown to large and the turtles are now nipping there fins. I am thinking of getting rid of them now (sell/trade/giveway), And am thinking of putting some other fish in there to do the same job as they are.
I was thinking try with some new small gold fish, or a small fish like guppies that could bread in there so that even if eaten they replace them selfs, what other options do I have?
The pond is 2m*1m by 0.5m deep, about 750l once I take out for steps.
Heres a few bad quality photos from my phone (taken when they were in a tank while I am cleaning the pond out):