The paper considers the model of hydrodynamic processes in the reactor - clarifier that uses filtering technology in a fluidized layer. Dynamic load ripple particles lead to a substantial increase in clean suspensions from the impurities. Simulation allows to determine the loss of pressure in different parts of the structure. The free flow of power component costs associated with the hydrostatic pressure and viscous friction forces in laminar flow. In the fluidized layer these costs are due to the grain loading parameters: diameter, density, porosity. On the basis of the proposed model of self-oscillatory movement of grain loading obtained relations for estimation of particle ripple effect on the value of head loss. Therefore necessary to average power in increments of hydraulic gradient is established. Analysis of hysteresis phenomena in various design modes spend, due to the fact that the height of the weighted layer is not a unique function of supplying treated water rate. It is shown that the occurrence of the hysteresis loop can be connected with the capture of the self-oscillation frequency of movement of the contact mass particles.