Is this your pond??? If so why is someone else putting anything into it? Friend or not no one but ME manages my pond. Otherwise you have things happen just like you stated above. It's going to be tuff to get rid of all 25 of them without killing out your pond like BK said. Even if you catch 20 of them it only takes 2 in that small of a pond to get going and in a year or 2 your in trouble.
Good Luck my friend,
