Place a layer of clean soil on the bottom of the water, and then add a layer of coarse sand (must be coarse). Then, for the sake of appearance and no mud, add a layer of smooth, unbleached stones. You can also plant some aquatic plants, such as hornworts, money grass, and water lilies, but not too many. In this way, the water will have the ability to clean itself.

You don’t need to add water every time you raise koi. Salt, it’s not a saltwater fish. In addition, you are changing the water incorrectly. At most, it should be 1/3 at a time. Although the koi has a solid skin, it is very sensitive to changes in water temperature. If too much water is changed at one time, the water temperature difference will be large, which is extremely serious. Easy to get sick.

In your current situation, clean the pond once. Don’t be afraid of trouble, disinfect it well, and raise water first, then raise fish. Let the fish have a simple and necessary period in the basin before putting new fish in. disinfection process to avoid damaging the water body.

There is another situation where the problem you mentioned will occur, that is, if you feed too much, the fish will not be able to eat them all, and the water body will deteriorate.

As the saying goes As the saying goes, "A pig that cannot survive, a fish that cannot starve to death", just don't feed it all the time.