We investigated possibility of realization of different resonant interaction on a discrete grid, characteristic for wave tanks and numerical simulations for both gravity and capillary waves. New type of instability of a standing wave proposes a simple mechanism for generation of an isotropic spectrum, convenient for wave turbulence experiments, through pumping of a one standing wave. This instability is realizable for any type of waves with dispersion relation depending only on the magnitude of a wave vector in systems with present four-waves interaction, for example both surface capillary and gravity waves. All analytical results were confirmed by numerical simulation, extending our previous work on the matter (A.I. Dyachenko, A.O. Korotkevich, V.E. Zakharov, Decay of the monochromatic capillary wave, JETP Lett., 77, 9, 477-481 (2003)).