Ion-stabilized gas nanobubbles (the so-termed "bubstons") and their clusters are investigated in bulk aqueous solutions of NaCl at different ion concentrations by four independent laser diagnostic methods. It turned out that in the range of NaCl concentration 10(-6) < C < 1 M the radius of bubston remains virtually unchanged at a value of 100 nm. Bubstons and their clusters are a thermodynamically non-equilibrium phase, which has been demonstrated in experiments with magnetic stirrer at different stirring rates. Different regimes of the bubston generation, resulting from various techniques of processing the liquid samples, were explored.