Just as a note, Rudd's are illegal in many states in the US, including Pennsylvania. They are banned in Canada. While not a major issue at this time, they are a non-native species and are considered to be an invasive species for the US and Canada.
For the EU they look like a great fish and potential population control as they will eat small fish on occasion. But they mostly feed on vegetation. They will eat pond food according to several fact sheets.