matija, welcome to the Pond Boss forum! I just spent some time on Wikipedia reading about your country, Montenegro; your language(s), Montenegrin and others; your fish species of interest, Common Rudd, bleak, and European perch. Those are not found "just anywhere" here in the USA. We do have plenty of carp and black bullheads.
I'm no expert, by any means, but it seems that you would have some good luck combining the perch as predators, with the bleak and the rudd as forage fish. The rudd get too big at 1.2 kilos for the perch to eat, but the perch certainly could eat the young rudd. The perch could overpopulate and stunt; your small pond could be easily fished hard to remove enough perch to prevent this stunting.
Can you cover the bottom of your pond with gravel as the Germans do when raising carp? Unless you can do this, I think carp and black bullheads would stir up the bottom mud so much that other fish could not see well enough to find enough food and then would grow slowly. With a gravel-bottomed pond and clear water, you could feed high-quality fish food. The carp, bullheads, and perch, and the "minnows", that is those forage fish-the rudds and the bleaks-also would benefit from the food, either by eating it directly, or by eating the plankton population that develops from the nutrients added to the water by the fish food.
In another post, you asked about dealing with the stunting problem of black bullheads. If your pond water is clear and your perch are numerous, the bullheads will get gobbled up when they are tiny, young fry. You also can net them and trap them to reduce their numbers.
Thanks for asking your questions here on Pond Boss. There may not be direct experience relative to all your issues, but this forum has enough accumulated knowledge and wisdom to help you on your journey.
Good luck. Hopefully, one of our resident experts will chime in with some help for you. Can you post any pictures of your land, and tell us more about where on your land you would build this pond?
