When the BBC's Katherine Latham made a pond with just a plant pot, some rocks and a few native pond plants, she was amazed at the speed wildlife moved in.
You definitely need the pump, the best thing about koi or gold fish is that they grow to the size of the environment. You also need to make sure that you have enough algae helping to oxygenate the water (for others reading, not necessarily you in particular).
It can take some work to get things just right but once it starts maintaining itself (for the most part) it becomes it’s own little world.
Some closing advice for those who live in the part of the world where it gets and stays at or below freezing for weeks or months on end, don’t mess with it when it freezes over. Turn off the pump and leave it alone, the fish will hibernate and will wake up when it’s warmer. This means keeping kids away from it that may want to poke at the ice.
You definitely need the pump, the best thing about koi or gold fish is that they grow to the size of the environment. You also need to make sure that you have enough algae helping to oxygenate the water (for others reading, not necessarily you in particular).
It can take some work to get things just right but once it starts maintaining itself (for the most part) it becomes it’s own little world.
Some closing advice for those who live in the part of the world where it gets and stays at or below freezing for weeks or months on end, don’t mess with it when it freezes over. Turn off the pump and leave it alone, the fish will hibernate and will wake up when it’s warmer. This means keeping kids away from it that may want to poke at the ice.