If and when I feed the fish, it's the same stuff I feed my dog....dog food. I love my dog, he gets good food.
Before I get banned from the site, let me explain.
I was feeding the fish dog food everyday last season and at the first "plop" sound, they'd come running...swimming.... as fast as they could to be first in line. It got to the point where if they saw me they'd come to the surface and wait. This caused two problems; The first being any image moving around the perimeter of the pond would draw them up. Even a heron. I don't want to feed the heron too. The second problem became their no-shame attitude of entitlement. Here I am taking the best care of them I know how, and they expect to be hand-fed too. Fortunately winter happened and they were left to their own devices for 4 1/2 months and it was get back to reality or starve. Out of approximately 70 fish I lost one, and that wasn't starvation it was stupidity. So I decided this spring, no more Mr Niceguy. They can get used to their natural cuisine or leave. So far nobody has left, starved, or even lost any weight, so I'm cutting way back on the welfare. They're doing fine eating the stuff carp eat. Call it "Tough Love".
I do treat them occasionally with some dog food though.