The article is devoted to studying the problems of physical modeling of acoustic and hydroacoustic waves, which are reflected from hydrobionts in recirculation aquatic systems (RAS), as well as open aquaculture cages (OAC). The behavior of aquatic organisms in RAS and OAC is so complex that it is difficult to be described mathematically because it is necessary to determine the temporal and spatial parameters of hydrobionts and to provide favourable conditions for aquatic organisms in RAS and OAC close to the natural habitat, including the acoustic regime. The use of simulation and physical modeling for calculating the acoustic quantities will make it possible to use machine vision to and optimize technological processes, to increase the productivity of the ultrasonic and ultrasonic treatment pools, to raise productivity and to reduce costs. The aim of acoustic quantities similarity in RAS and OAC is to determine the parameters of sound sources, the reflecting ability of hydrobionts with different characteristics (length, volume, density and others). In the problems of acoustic quantities it is required to ensure the coincidence of mechanical and acoustic processes. It is necessary to reduce the quantities dependent on the dimensional attributes of the object (length of a sound wave, sound power, sound energy, sound intensity, speed of sound, frequency, etc.) to their independent dimensionless form. When studying the behavior of aquatic organisms in RAS and OAC it is important to take into account mechanical, hydrodynamic, electrodynamic, optical and light similarities. There have been proposed the additional similarity scales for acoustic values, the methods for their calculation and the graphs of their dependence on the geometric scale Cl. Knowing the scale of Cl, it is possible to determine the scale effect