If the fish are at the lowest level, the pool water level is very important and the water depth and water flow rate can be reduced (depending on the type, size or species of fish), while the fish species will benefit from a larger volume of water. And show better performance at higher water velocities.
In a round pool, or in an octagonal pool, water moves in a circular pattern that drives the entire water column around the center. Organic particles provide a relatively short residence time of a few minutes, depending on the size of the fish pond due to the hydraulic flow of water and the self-purification effect of the fish pond structure, vertical inlet adjustment is an efficient way to control water flow in such ponds.
Of course, if fish ponds are effectively stored with fish, the effect of self-purification of fish ponds with fish activity will be better and more appropriate. In designing a fish pond, the slope of the pond (depending on the species and type of fish) does not have much of an effect on waste disposal performance, but makes it easier when fully discharged.